Francke shared these thoughts in an article on the best way to preach.
“It might probably make some good impressions on the minds of the people, were a minister pretty often to inculcate, with great plainness and seriousness, the necessity of prayer; and more particularly what need they have to pray very earnestly to the God of grace that he would set home his word upon their hearts. that he would bring the good deed to perfection in their full and blessed conformity to himself. And further, so great is the ignorance of many persons concerning the duty of prayer, that they seem to have no other notion of it than merely a leading some forms out of a prayer-book.
This makes it to be as necessary, as it would properly be a useful thing for a minister to lead them, as it were, by the hand, into this path of duty: that is, to explain it to them in a most easy and familiar manner, to show them that it requires no great art and skill to pray acceptably unto God; for they are to speak to him as children to a loving father, they are to spread before him their sorrows and complaints, they are to tell him of the state and condition of their souls, just as they find and feel it; and they need not be at all solicitous about propriety of expression and elegant phrases in their secret prayers; for God regards the sense of the heart, rather than the language of the lips. The scriptures themselves furnish us with several examples of such artless and yet acceptable prayers.
Let a minister then diligently instruct his hearers how they are, in the first place, to get their hearts disposed for prayer; and it may be of use too to assist and furnish the more ignorant with words and fit expressions; but at the same time let him inform them that they need not tie themselves to use those very words, nor any form whatever; but that they should learn to pour out their hearts unto God, in such words by which they can best express the real sentiments and affections of their own souls, according to the Psalmist, Psalm 62:8, “Ye people, pour out your hearts before him.”
Taken from the Most Useful Way of Preaching by August Francke