Luther is commemorated by Lutherans on this date, the anniversary of his death in 1546. We may be so bold as to note that the Roman Missal provides a collect that Luther might have appreciated:
"O God, who seest that we put not our trust in any thing that we do: mercifully grant, that by the protection of the Doctor of the Gentiles we may be defended against all adversities. Through our Lord . . ." (Collect for Sexagesima Sunday)
It was in part external threat of invasion that brought pressure to bear on talks between Luther, his fellow reformers and the Catholic Church resulting in the Augsburg Confession and later confessional writings. No doubt at this time internal disunity was not something to be desired by Charles V and the Holy Roman Empire while the Empire faced external adversities. When there are times of stress confession may be clearer but this same confession may also be forced and patience may be short.
The above collect could easily reflect those difficult days. On the one hand, Luther and the Augsburg Confessors insisting that we cannot trust in any thing that we do but in God and His mercy and the Roman Church and Empire seeking unity and assurance in the face of adversity. The collect draws these concerns together and unites them under the merciful protection of the Lord.
Without knowing the history of this particular collect it is a happy coincidence that this prayer is found in the Catholic liturgy during the week of this commemoration. In spite of any real differences of which we are reminded of on a regular basis, Luther would most probably be glad to pray this Catholic prayer today as if it were one he wrote himself.