A few weeks ago, you mentioned that it is not wrong to teach young children simple prayers that they can repeat. But would that not encourage vain repetitions (cf. Mt 6:7) and hypocrisy?
No, I do not think so.
In the first place, I do not think that we should apply Matthew 6:7 to young children. The Lord is, no doubt, warning adults who ought to know better about the foolishness of meaningless repetitions such as the kind practised by those who use a rosary to repeat prescribed phrases and prayers hoping to be heard.
In the second place, the Lord Jesus says: “Suffer the little children to come unto me, and forbid them not: for of such is the kingdom of God” (Mk 10:14). It appears to me that the way to encourage the little ones to go to the Lord is to encourage them to pray and to worship Him. I don’t think there is a danger of hypocrisy simply because it is unlikely that the child has the capacity to understand what is required of him to worship in spirit and in truth.
In the third place, we should understand that until the child is regenerated, he will not be able to truly pray. As long as he is not yet regenerated, he is dead in sin and trespasses (Eph 2:1). He cannot truly pray just as a corpse cannot breathe. Prayer is like spiritual breathing. But when the child is regenerated, he is spiritually resurrected and he will begin to pray naturally just as every living person will breathe naturally.
In the fourth place, though we do not know if the child is elect or not, if he is a covenant child, we have the divine warrant to regard him as belonging to the Lord; and therefore we have the duty to teach him to pray. But if he is unregenerate, he is unable to pray and even if he is regenerate (and it is can be hard to tell in the case of a child) he may still not know how to pray (remember how the disciples needed to be taught to pray). Therefore it behooves us to help him in what ways are suitable to his ability to prayer. Giving the child a simple prayer to repeat may just serve the purpose. If the child is unregenerate the prayer may serve as a kind of spiritual ventilator (remember that prayer is like spiritual breathing). If the child is regenerate or eventually experiences regeneration, the pattern of prayer taught him as a child may help him to formulate his own prayers much like how the Lord’s Prayer would help the Lord’s disciples formulate their own prayers.