This week’s collect stems from Gallicanum (from Gaul), Gelasian (relating to Pope Gelasius), and Gregorian (10th century, but misattributed to Pope Gregory the Great) liturgical books as prayers for those who were heretics and schismatics to be brought to repentance and come back into the historic faith of the church. It is now used in the Prayer Book as a general collect that prays for all those who have abandoned the Christian faith.
Second Sunday in Lent (BCP 1979)
O God, whose glory it is always to have mercy: Be gracious
to all who have gone astray from your ways, and bring them
again with penitent hearts and steadfast faith to embrace and
hold fast the unchangeable truth of your Word, Jesus Christ
your Son; who with you and the Holy Spirit lives and reigns,
one God, for ever and ever. Amen.
(Sources: Commentary on the American Prayer Book by Marion Hatchett and the 1979 American Book of Common Prayer)