Catechism Question #87 (October)
Q. What doth the preface of the Lord's Prayer teach us?
A. The preface of the Lord's Prayer, which is, Our Father which art in heaven, teaches us to draw near to God with all holy reverence and confidence, as children to a father, able and ready to help us; and that we should pray with and for others.
1 John 5:14-15 - Now this is the confidence that we have in Him, that if we ask anything according to His will, He hears us. And if we know that He hears us, whatever we ask, we know that we have the petitions that we have asked of Him.