If this guy is a friend, you are obligated to lead him to the truth that is, of course, in the Word. Suggest that he read Ephesians 5:25-31. If this 'Buddy' had been "washing" is wife with the pure water of the word as a so called minister should do, he wouldn't want to leave her.Also, ask him what he thinks Jesus meant when he spoke to the Pharisees about this issue recorded in Matthew 19:3-9. Remember, it's really not about this Buddy going into ministry or writing a book about his situation. It's all about his obedience or the lack thereof. Paul gives very specific instructions about the marriage union in 1 Cor. 7 when he says, "..the husband should not divorce (or leave) his wife." This is not optional! This is a command! In verses 10 & 11 it is very specific: "..the wife should not leave her husband...and the husband should not leave his wife."There is no way around this. If this Buddy of yours has left his wife, he is in a state of rebellion to God. Should he then go into 'ministry'? Anyone can have a 'ministry'. The devil worshipers and cultists have 'ministries.' That is really not the issue unless he is leading others astray. Then what Jesus said in Mat. 18:7 applies: "Woe to the world because of its stumbling blocks! For it is inevitable that stumbling blocks come; but woe to that man through whom the stumbling block comes!"You can help your friend by guiding him lovingly to some of these scriptures. If he listens to you, you have won your brother. If he doesn't, take two or three others with you and if he still doesn't listen to you, tell it to the church and then if he still doesn't change, put him out of the fellowship and treat him as a pagan. (See Mat. 18:15-17)Don't be afraid of losing a friend by showing him what the Word says. You will gain for yourself by your obedience.