15th Sunday: OT: Collect

Deus, qui errantibus, ut in viam possint redire, veritatis tuae lumen ostendis, da cunctis, qui christiana professione censentur, et illa respuere, quae huic inimica sunt nomini,  et ea quae sunt apta sectari.

From Liber locorum communium: Steve Perisho

"the grace to reject whatever is contrary to the name of Christ and to strive after all that does it honour."

O God, who show the light of your truth to those who go astray, so that they may return to the right path, give all who for the faith they profess are accounted Christians the grace to reject whatever is contrary to the name of Christ and to strive after all that does it honour.  Through our Lord Jesus Christ, [etc.]

     Collect for the Fifteenth Sunday in Ordinary Time, Roman missal, as re-translated in 2010, and, in the pre-2010 translation below, the Liturgy of the hours as well.  =Corpus orationum no. 1582A-B =Bruylants no. 336.  It goes back to the late 6th- (according to the ODCC the early 7th-) century Leonine sacramentary (Verona, Biblioteca capitolare LXXXV), in which it is no. 75.  See p. 9 of the older edition of that ed. Feltoe, where it appears under April.  The 8th-century Gelasian sacramentary (Vat. Regin. lat. 316), in which it is no. 546, "preserved the tradition of appointing it for th[e Third] Sunday [after Easter]" more specifically, which is where (following, presumably, the Salisbury rite) it appears in the 1549-1928 Book of common prayer, too (below), as "One of the oldest in the Prayer Book" (Shepherd, Oxford American prayer book commentary (1950), p. 173).  See, for example, the older edition of the Gelasian ed. Wilson, pp. 102-103, for some variants (including the reading "way of righteousness", in square brackets below), and Corpus orationum for even more.  Here is how it appears in the 3rd typical edition (The CTS new daily missal (2012), p. 552):

Deus, qui errantibus, ut in viam possint redire [justitiae], veritatis tuae lumen ostendis, da cunctis qui christiana professione censentur, et illa respuere, quae huic inimica sunt nomini, et ea quae sunt apta sectari. Per, [etc.]

Pre-2010 translation of the Missal as reproduced by Fr. Z and in the current Liturgy of the hours:

God our Father,

your light of truth

guides us to the way of Christ.

May all who follow him

reject what is contrary to the gospel.

1549 Book of common prayer for the Third Sunday after Easter (which is where it appears through the 1928 BCP), as reproduced in the Everyman's Library edition of 1910:

Almightye God, whiche shewest to all men that be in errour the light of thy truth, to the intent that they maie returne into the waye of righteousness; Graunt unto all them that bee admitted into the felowship of Christes religion, that they maye exchew those thinges that be contrary to their profession, and folow all such thinges as be agreable to the same; through [etc.]

1928 Book of common prayer for the Third Sunday after Easter:

Almighty God, who showest to them that are in error the light of thy truth, to the intent that they may return into the way of righteousness; Grant unto all those who are admitted into the fellowship of Christ's Religion, that they may avoid those things that are contrary to their profession, and follow all such things as are agreeable to the same; through [etc.]