Roman Catechism 34.36

Chapter 34 — Part IV: Prayer — The Lord's Prayer: Introduction and Our Father Who Art in Heaven

Section 36. In this remembrance and in this thought, consider with what fervour and piety you should pray. Endeavour to act as becomes a child of God; that is to say, see that your prayers and actions are never unworthy of that divine origin with which He has been pleased in His infinite bounty to ennoble you. It is to the discharge of this duty that the Apostle exhorts us when he says: Be ye therefore imitators of God as most dear children, so that what the Apostle wrote to the Thessalonians may be truly said of us: You are all the children of light, and the children of the day.