Hear, ye children, the instruction of a father, and attend to know understanding. For I give you good doctrine, forsake ye not my law.Proverbs 4:1-2
Whom shall he teach knowledge? and whom shall he make to understand doctrine? them that are weaned from the milk, and drawn from the breasts. For precept must be upon precept, precept upon precept; line upon line, line upon line; here a little, and there a little:Isaiah 28:9-10
Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: 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:Ephesians 4:13-15
Let no man despise thy youth; but be thou an example of the believers, in word, in conversation, in charity, in spirit, in faith, in purity. Till I come, give attendance to reading, to exhortation, to doctrine. Neglect not the gift that is in thee, which was given thee by prophecy, with the laying on of the hands of the presbytery. Meditate upon these things; give thyself wholly to them; that thy profiting may appear to all. Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee.1 Timothy 4:12-16
But thou hast fully known my doctrine, manner of life, purpose, faith, longsuffering, charity, patience, Persecutions, afflictions, which came unto me at Antioch, at Iconium, at Lystra; what persecutions I endured: but out of them all the Lord delivered me. Yea, and all that will live godly in Christ Jesus shall suffer persecution. But evil men and seducers shall wax worse and worse, deceiving, and being deceived. But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them; And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: That the man of God may be perfect, throughly furnished unto all good works.2 Timothy 3:10-17
Young men likewise exhort to be sober minded. In all things shewing thyself a pattern of good works: in doctrine shewing uncorruptness, gravity, sincerity,Titus 2:6-7
For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God; and are become such as have need of milk, and not of strong meat. For every one that useth milk is unskilful in the word of righteousness: for he is a babe. But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil. Therefore leaving the principles of the doctrine of Christ, let us go on unto perfection; not laying again the foundation of repentance from dead works, and of faith toward God, Of the doctrine of baptisms, and of laying on of hands, and of resurrection of the dead, and of eternal judgment. And this will we do, if God permit.Hebrews 5:12-6:3
The Scripture is very clear; children must learn sound doctrine. This learning should come from their parents at an early age. It is this doctrine that will keep them from error and bring about their salvation. Doctrine is simply truths drawn from Scripture.
One of the greatest ways to teach a child sound doctrine is through the use of a catechism. A catechism is a series of questions and answers that systematically teaches the child sound doctrine. The child memorizes the answers, and the parent shows the child why the answers are true from Scripture.