Kingdom Service Is Not a Professional Gig
The above link from professor J.D. Payne was written while he was at a very consistently trustworthy seminary (I believe now he is a church planting pastor with David Platt's ministry).
His point deals with the morally incorrect mindset found today about the world and even, yes, in church attenders who haven't worked through it yet, that they cannot serve the Lord Jesus' kingdom for "fill in the blank" reason. Namely, excuses like 'I don't have time,' or the common 'I don't know enough,' or even 'I cannot afford to' are obstacles to God's will for our lives.
In effect, while he doesn't put it this way, positively stated: this is a challenge to obey Jesus' model: The Son of Man came not be served, but to serve. If we want to be like Jesus, then we should not pretend He is only a psychological lozenge, but also a great King worth living for today.
Some good stuff, be blessed.