Commodian — Instructiones 46

I warn the faithful that brothers not take up hatreds: impious hatreds are counted to the fire for martyrs; the martyr is destroyed whose confession is such. Law is given the unjust so he can rein himself; thence washed, you likewise ought to be free of it. Twice you sin against God who stretch quarrels to a brother. From which you will not escape sin if you keep pursuing the old way. You are washed once — will you be able to be dipped again?