Today the Church celebrates St. Francis of Assisi, whom some consider to be the most Christ-like of the saints in his humility and childlike nature. That invitatory above is from the common for saints, and it struck me as truly most apt for il Poverello, who was a great sinner before he became a great saint. A hedonist who became an ascetic, pretty much. Once worldly who became heavenly. The glory of God shows in this great work of salvation -- which is precisely why the lives of the saints are wonderful spiritual reading for us.
I too am a great sinner, but the Lord's mercy is greater than the greatest sin, and the Lord is glorious in his saints. Come let us adore him! Adeste adoremus!"