Roman Catechism 36.30

Chapter 36 — Part IV: Prayer — The Second Petition: Thy Kingdom Come

Section 30. This consideration should excite in us humility and lowliness. Thus our prayers will be full of Christian humility; and wholly distrusting ourselves, like the publican, we will fly to the mercy of God. Attributing all to His bounty we will render immortal thanks to Him who has imparted to us that Holy Spirit, relying on whom we are emboldened to say: Abba (Father).