Romans 15:20
I make it my ambition to preach the gospel, not where Christ has already been named, lest I build on someone else's foundation

I would rather win souls than be the greatest king or emperor on earth; I would rather win souls than be the greatest general that ever commanded an army; I would rather win souls than be the greatest poet, or novelist, or literary man who ever walked this earth. My one ambition in life is to win as many as possible.
R.A. Torrey