As for such as turn aside unto their crooked ways, the LORD shall lead them forth with the workers of iniquity: but peace shall be upon Israel. That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive; But speaking the truth in love, may grow up into him in all things, which is the head, even Christ: From whom the whole body fitly joined together and compacted by that which every joint supplieth, according to the effectual working in the measure of every part, maketh increase of the body unto the edifying of itself in love.
~ Psalm 125:5, Ephesians 4:14-15
But he that shall endure unto the end, the same shall be saved. Who are kept by the power of God through faith unto salvation ready to be revealed in the last time. Rooted and built up in him, and stablished in the faith, as ye have been taught, abounding therein with thanksgiving. Now unto him that is able to keep you from falling, and to present you faultless before the presence of his glory with exceeding joy, That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;
~ Matthew 24:13, 1 Peter 1:5, Colossians 2:7, Jude 1:24, Ephesians 3:17, Hebrews 3:14
Therefore whosoever heareth these sayings of mine, and doeth them, I will liken him unto a wise man, which built his house upon a rock: And the rain descended, and the floods came, and the winds blew, and beat upon that house; and it fell not: for it was founded upon a rock. But the anointing which ye have received of him abideth in you, and ye need not that any man teach you: but as the same anointing teacheth you of all things, and is truth, and is no lie, and even as it hath taught you, ye shall abide in him.
~ Matthew 7:24-25, 1 John 2:27
A Preliminary Discourse to Catechising, by Thomas Watson. This is from his work, “A Body of Divinity”.
If ye continue in the faith grounded and settled, and be not moved away from the hope of the gospel, which ye have heard, and which was preached to every creature which is under heaven; whereof I Paul am made a minister;
~ Colossians 1:23
Intending next Lord’s day to enter upon the work of catechising, it will not be amiss to give you a preliminary discourse, to show you how needful it is for Christians to be well instructed in the grounds of religion. If ye continue in the faith grounded and settled.’
I. It is the duty of Christians to be settled in the doctrine of faith.
II. The best way for Christians to be settled is to be well grounded.
I. It is the duty of Christians to be settled in the doctrine of faith. It is the apostle’s prayer, I Peter 5:50, ‘The God of all grace stablish, strengthen, settle you.’ That is, that they might not be meteors in the air, but fixed stars. The apostle Jude speaks of wandering stars, in verse 13. They are called wandering stars, because, as Aristotle says, They do leap up and down, and wander into several parts of the heaven; and being but dry exhalations, not made of that pure celestial matter as the fixed stars are, they often fall to the earth.’ Now, such as are not settled in religion, will, at one time or other, prove wandering stars; they will lose their former steadfastness, and wander from one opinion to another. Such as are unsettled are of the tribe of Reuben, unstable as water,’ Genesis 49:9; like a ship without ballast, overturned with every wind of doctrine. Beza writes of one Belfectius, that his religion changed as the moon. The Arians had every year a new faith. These are not pillars in the temple of God, but reeds shaken every way. The apostle calls them damnable heresies.’ 2 Peter 2:2. A man may go to hell as well for heresy as adultery. To be unsettled in religion, argues want of judgement. If their heads were not giddy, men would not reel so fast from one opinion to another. It argues lightness. As feathers will be blown every way, so will feathery Christians. Triticum non rapit ventus inanes palae jactantur. Cyprian. Therefore such are compared to children. Ephesians 4:44. That we be no more children, tossed to and fro.’ Children are fickle sometimes of one mind sometimes of another, nothing pleases them long; so unsettled Christians are childish; the truths they embrace at one time, they reject at another; sometimes they like the Protestant religion, and soon after they have a good mind to turn Papists.
 It is the great end of the word preached, to bring us to a settlement in religion. Ephesians 4:41, 12, 14. And he gave some, evangelists; and some, pastors and teachers; for the edifying of the body of Christ; that we henceforth be no more children.’ The word is called a hammer. Jeremiah 23:39. Every blow of the hammer is to fasten the nails of the building; so the preacher’s words are to fasten you the more to Christ; they weaken themselves to strengthen and settle you. This is the grand design of preaching, not only for the enlightening, but for the establishing of souls; not only to guide them in the right way, but to keep them in it. Now, if you be not settled, you do not answer God’s end in giving you the ministry.
 To be settled in religion is both a Christian’s excellence and honour. It is his excellence. When the milk is settled it turns to cream; now he will be zealous for the truth, and walk in close communion with God. And his honour. Proverbs 16:61. The hoary head is a crown of glory, if it be found in the way of righteousness.’ It is one of the best sights to see an old disciple; to see silver hairs adorned with golden virtues.
 Such as are not settled in the faith can never suffer for it. Sceptics in religion hardly ever prove martyrs. They that are not settled hang in suspense; when they think of the joys of heaven they will espouse the gospel, but when they think of persecution they desert it. Unsettled Christians do not consult what is best, but what is safest. The apostate (says Tertullian) seems to put God and Satan in balance, and having weighed both their services, prefers the devil’s service, and proclaims him to be the best master: and, in this sense, may be said to put Christ to open shame.’ Hebrews 6:6. He will never suffer for the truth, but be as a soldier that leaves his colours, and runs over to the enemy’s side; he will fight on the devil’s side for pay.
 Not to be settled in the faith is provoking to God. To espouse the truth, and then to fall away, brings an ill report upon the gospel, which will not go unpunished. Psalm 78:87, 59. They turned back, and dealt unfaithfully. When God heard this, he was wroth, and greatly abhorred Israel.’ The apostate drops as a wind-fall into the devil’s mouth.
 If ye are not settled in religion, you will never grow. We are commanded to grow up into the head, even Christ.’ Ephesians 4:15. But if we are unsettled there is no growing: the plant which is continually removing never thrives.’ He can no more grow in godliness, who is unsettled, than a bone can grow in the body that is out of joint.
 There is great need to be settled, because there are so many things to unsettle us. Seducers are abroad, whose work is to draw away people from the principles of religion. I John 2:26. These things have I written unto you concerning them that seduce you.’ Seducers are the devil’s factors; they are of all others the greatest felons that would rob you of the truth. Seducers have silver tongues, that can put off bad wares; they have a sleight to deceive. Ephesians 4:14. The Greek word there is taken from those that can throw dice, and cast them for the best advantage. So seducers are impostors, they can throw a dice; they can so dissemble and sophisticate the truth, that they can deceive others. Seducers deceive by wisdom of words. Romans 16:18. By good words and fair speeches they deceive the hearts of the simple.’ They have fine elegant phrases, flattering language, whereby they work on the weaker sort. Another sleight is a pretence of extraordinary piety, that so people may admire them, and suck in their doctrine. They seem to be men of zeal and sanctity, and to be divinely inspired, and pretend to new revelations. A third cheat of seducers is, labouring to vilify and nullify sound orthodox teachers. They would eclipse those that bring the truth, like black vapours that darken the light of heaven; they would defame others, that they themselves may be more admired. Thus the false teachers cried down Paul, that they might be received, Galatians 4:17. The fourth cheat of seducers is, to preach the doctrine of liberty; as though men are freed from the moral law, the rule as well as the curse, and Christ has done all for them, and they need to do nothing. Thus they make the doctrine of free grace a key to open the door to all licentiousness. Another means is, to unsettle Christians by persecution.2 Timothy 3:12. The gospel is a rose that cannot be plucked without prickles. The legacy Christ has bequeathed is the cross. While there is a devil and a wicked man in the world, never expect a charter of exemption from trouble. How many fall away in an hour of persecution! Revelation 12:2. There appeared a great red dragon, having seven heads and ten horns; and his tail drew the third part of the stars of heaven.’ The red dragon, by his power and subtilty, drew away stars, or eminent professors, that seemed to shine as stars in the firmament of the church.
To be unsettled in good is the sin of the devils. Jude 6. They are called, morning stars,’ Job 38:8, but falling stars;’ they were holy, but mutable. As the vessel is overturned with the sail, so their sails being swelled with pride, they were overturned. I Timothy 3:3. By unsettledness, men imitate lapsed angels. The devil was the first apostate. The sons of Sion should be like mount Sion, which cannot be removed.
II. The second proposition is, that the way for Christians to be settled is to be well grounded. If ye continue grounded and settled.’ The Greek word for grounded is a metaphor which alludes to a building that has the foundation well laid. So Christians should be grounded in the essential points of religion, and have their foundation well laid.
Here let me speak to two things:
 That we should be grounded in the knowledge of fundamentals. The apostle speaks of the first principles of the oracles of God.’ Hebrews 5:12. In all arts and sciences, logic, physic, mathematics, there are some praecognita, some rules and principles that must necessarily be known for the practice of those arts; so, in divinity, there must be the first principles laid down. The knowledge of the grounds and principles of religion is exceedingly useful.
(1.) Else we cannot serve God aright. We can never worship God acceptably, unless we worship him regularly; and how can we do that, if we are ignorant of the rules and elements of religion? We are to give God a reasonable service.’ Romans 12:2: If we understand not the grounds of religion, how can it be a reasonable service?
(2.) Knowledge of the grounds of religion much enriches the mind. It is a lamp to our feet; it directs us in the whole course of Christianity, as the eye directs the body. Knowledge of fundamentals is the golden key that opens the chief mysteries of religion; it gives us a whole system and body of divinity, exactly drawn in all its lineaments and lively colours; it helps us to understand many of those difficult things which occur in the reading of the word; it helps to untie many Scripture knots.
(3.) It furnishes us with armour of proof; weapons to fight against the adversaries of the truth.
(4.) It is the holy seed of which grace is formed. It is semen fidei, the seed of faith. Psalm 9:10. It is radix amoris, the root of love. Ephesians 3:17. Being rooted and grounded in love.’ The knowledge of principles conduces to the making of a complete Christian.
 This grounding is the best way to being settled: grounded and settled.’ A tree, that it may be well settled, must be well rooted; so, if you would be well settled in religion, you must be rooted in its principles. We read in Plutarch of one who set up a dead man, and he would not stand. Oh,’ said he, there should be something within.’ So, that we may stand in shaking times, there must be a principle of knowledge within; first grounded, and then settled. That the ship may be kept from overturning, it must have its anchor fastened. Knowledge of principles is to the soul as the anchor to the ship, that holds it steady in the midst of the rolling waves of error, or the violent winds of persecution. First grounded and then settled.
Use one: See the reason why so many people are unsettled, ready to embrace every novel opinion, and dress themselves in as many religions as fashions; it is because they are ungrounded. See how the apostle joins these two together, ‘unlearned and unstable.’ 2 Peter 3:16. Such as are unlearned in the main points of divinity are unstable. As the body cannot be strong that has the sinews shrunk; so neither can that Christian be strong in religion who wants the grounds of knowledge, which are the sinews to strengthen and stablish him.
Use two: See what great necessity there is of laying down the main grounds of religion in a way of catechising, that the weakest judgement may be instructed in the knowledge of the truth, and strengthened in the love of it. Catechising is the best expedient for the grounding and settling of people. I fear one reason why there has been no more good done by preaching, has been because the chief heads and articles in religion have not been explained in a catechistical way. Catechising is laying the foundation. Hebrews 6:6: To preach and not to catechise is to build without foundation. This way of catechising is not novel, it is apostolic. The primitive church had their forms of catechism, as those phrases imply, a form of sound words,’ 2 Timothy 1:13, end the first principles of the oracles of God,’ Hebrews 5:52. The church had its catechumenoi, as Grotius and Erasmus observe. Many of the ancient fathers have written for it, as Fulgentius, Austin, Theodoret, Lactantius, and others. God has given great success to it. By thus laying down the grounds of religion catechistically, Christians have been clearly instructed and wondrously built up in the Christian faith, insomuch that Julian the apostate, seeing the great success of catechising, put down all schools and places of public literature, and instructing of youth. It is my design, therefore (with the blessing of God); to begin this work of catechising the next Sabbath day; and I intend every other Sabbath, in the afternoon, to make it my whole work to lay down the grounds and fundamentals of religion in a catechistical way. If I am hindered in this work by men, or taken away by death, I hope God will raise up some other labourer in the vineyard among you, that may perfect the work which I am now beginning.