The adversaries, in the Confutation, have also quoted Colossians 3:14 against us, “love, which binds everything together in perfect harmony.” From this they conclude that love justifies because it makes people perfect … This is far from Paul’s meaning, who never allows Christ to be excluded from the Atonement. Therefore, he speaks not about personal perfection, but about the integrity common to the Church. For this reason, he says that love is a bond or connection to show that he speaks about the binding and joining together of the many members of the Church. In all families and in all states unity should be nourished by mutual offices, and peace cannot be maintained unless people overlook and forgive certain mistakes among themselves. In a similar way, Paul commands that there should be love in the Church in order that it may preserve unity, bear with the harsher manners of brethren as there is need, and overlook certain less serious mistakes. This must happen or else the Church will fly apart into various schisms, and hostilities and factions and heresies will arise from the schisms.
…. On the other hand, perfection (i.e., the Church’s integrity) is preserved when the strong bear with the weak, when the people put up with some faults in the conduct of their teachers, and when the bishops make some allowances for the people’s weakness. … Furthermore, it is disgraceful for the adversaries to preach so much about love while they don’t show it anywhere. What are they doing now? They are tearing apart churches. They are writing laws in blood and asking the most merciful prince, the emperor, to enforce them. They are killing priests and other good men if any one of them has slightly indicated that he does not entirely approve of their clear abuses. What they are doing is not consistent with their claims of love, which if the adversaries would follow, the churches would be peaceful and the state would have peace. This turmoil would be lessened if the adversaries would stop being so bitter about certain traditions. … The adversaries easily forgive themselves, but do not likewise forgive others according to the passage in the poet, “‘I forgive myself,’ Maevius said.”
Concordia, p. 116-117