Thanks, Dr, it's very much apreciated and needed.
I'm on a short leash today, so I'll have to hurry.
First...here are my thoughts: God is the Author of life, and although it would not be the "unpardonable sin" to wrest control over that out of His hands, it would definitely be in direct opposition to the clear, stated will of God for your friend to do so. When at any time in history have you known someone to go directly against the revealed will of God and in so doing have made things better for people around him? (God can work things out to redeem the situation, but why be the cause of that in the first place?) Also, I would put before you the verse that says "Therefore, choose LIFE, that you and your children may live..." In other words, God's perfect will for us, as revealed in Scripture, is to choose life.
Lastly, I believe Starwind said it best so far (haven't read entire thread yet), so I'm going to repeat those comments here:
"The greatest good, that of exalting Jesus Christ and making disciples of all nations, is best served by the witness and testimony of transformed lives.
"For your friend to take his own life serves no purpose. True believers will know your friend denied Christ's forgiveness and His healing, transformative power. Non-believers will scoff and conclude your friend was another misguided person who placed his happiness on the empty promises of religion.
"On the other hand, your friend should consider what a powerful testimony he could give on Christ's forgiveness and healing in his own life. Further, God may have allowed these trials into your friend's life so that your friend, somewhere down the road, can be an encouraging counselor to other troubled souls to whom only he can relate and demonstrate to them that Jesus can help them as well.
"As DrSteveJ said, your friend needs immediate competent spiritual and medical help. He can be an example of an overcomer in Christ, or a succumber in the world. Which serves God better?"
My parting thoughts---he needs direct intervention, and if he can't even keep an appointment with a counselor, then it may be time for those around him to gather up the pallet and literally carry him to help (as those friends did for the man in the New Testament when they let him down through the roof so that he could be healed).
Those are my thoughts. I pray God will bring victory in this.