The Commendation of Good Character
2Cor 6:6 in purity, understanding, patience and kindness; in the Holy Spirit and in sincere love;
The ministry is not just about right doctrine, nor about being zealous as revealed by one's endurance in the face of opposition. It's about everything. One's attitude, understanding, the way we treat others and our motivation.
Paul advises Timothy, "Don’t let anyone look down on you because you are young, but set an example for the believers in speech, in life, in love, in faith and in purity." 1Tim 4:12 So "Flee the evil desires of youth, and pursue righteousness, faith, love and peace, along with those who call on the Lord out of a pure heart." 2Tim 2:22
Consider for example sincere love. Much as ministry can be viewed among the mature as a matter of duty, sincere love goes beyond duty. This is not to say that those who enjoy doing the ministry have sincere love, but rather those who take genuine interest in the welfare of others despite the hardship of doing so. Paul writes of Timothy, "I have no one else like him, who takes a genuine interest in your welfare. For everyone looks out for his own interests, not those of Jesus Christ." Php 2:20,21 Sincere love is indeed a rare quality, even among ministers. Though they may appear sincere outwardly, most recognize how shallow and self-serving their interests often end up being. And this was apparently the case even among Paul's team.