It is worth to note the motivation when one does evangelism. What drives it? God can use any form of evangelism, even those that are done out of ill intent. Of course, since He is almighty and even the evil deeds are used to further His purposes… He is in control.
Php 1:15-18 Some indeed even preach Christ because of envy and strife, and some also of good will. (16) Those, indeed, preach Christ out of contention, not sincerely, supposing to add affliction to my bonds. (17) But these others preach in love, knowing that I am set for the defense of the gospel. (18) What then? Nevertheless, in every way, whether in pretense or in truth, Christ is preached. And I rejoice in this. Yet, also I will rejoice.
But for the Christian, the motivation is just as important as the action. Is it done because of true obedience to God, or is it done for some secret ulterior motive? That is why the best evangelism is done to those whom we find ‘hard’ to love and not to those that are easily loved (except for our family… which I would argue falls more easily in the former). How we act really would show the extent of our understanding of God’s commission to us. It will also show where our hope is… on the God who saves sinners or on the self who seeks people for their self-indulgence.