Here is a Biblical Argument against Donastism, a ancient Hersey that taught that the effective administration of the sacrament was based on the ministers holiness. In Philippians Paul teaches against such thinking:
Philippians 1:15-18 15 Some indeed preach Christ from envy and rivalry, but others from good will. 16 The latter do it out of love, knowing that I am put here for the defense of the gospel. 17 The former proclaim Christ out of rivalry, not sincerely but thinking to afflict me in my imprisonment. 18 What then? Only that in every way, whether in pretense or in truth, Christ is proclaimed, and in that I rejoice. Yes, and I will rejoice,
Here Paul is saying that the motive behind preaching the Gospel is not of concern, but rather that the Gospel is preached correctly.