It is true that some preach Christ out of envy and rivalry, but others out of goodwill. The latter do so in love, knowing that I am put here for the defense of the gospel. The former preach Christ out of selfish ambition, not sincerely, supposing that they can stir up trouble for me while I am in chains. But what does it matter? The important thing is that in every way, whether from false motives or true, Christ is preached. And because of this I rejoice. Paul Philippians 1:15-18I worry perhaps too much about motives. Jesus seemed to point to the importance of motives in the Divine assessment of action and life. But What does it matter?. Joey in Missions and Theology points out "In essence he was saying, their motives are between them and God. Whether the preaching was done for false motives or pure, whether for show or for the sake of what was right, Paul was genuinely pleased that the gospel was being spread."
What does it matter as long as the gospel is being proclaimed in some way? People's impure hearts and motives doesn't matter as long as God remains centre stage. I suppose this is where it is. If the person becomes centre stage then there is a problem. Whether preacher or worship leader if it is all about me, then we've entered idolatry - substituting us for God. I have not quite understood the N. American phenomenon of the "secret of" or "how to" book titles. Now I think it is all about the author and is a new form of the older gnosticism appearing in society. Perhaps also revealed in a renewed interest in the Gnostic gospels as well. For us below re: peoples actions and words, as long as Christ is preached then motives become secondary, as long as God is in centre then an impure heart is not the issue. God sees, searches and knows the hearts of humans.