[jodrellblank]

Maybe because instead of "being his friend" you are telling him he isn't good enough, trying to 'fix' his life for him, getting annoyed at how he isn't trying hard enough for you.

"If I really wanted something, and someone offered me the opportunity to do it, yes, it may fail and I may lose that friendship, but if that stops me, it means I don't believe in myself enough"

And what if you don't really want something, and someone offered you the opportunity to do it, and you didn't do it, would that mean you don't believe in yourself?

But it's the same trap, you see? He does not want to do it, because he is afraid of failing

That's why you think he doesn't want to do it, maybe. That's what you think your answer would be if you were in his shoes, maybe. Do you actually know why he doesn't want to do it? Have you asked? And listened to his reply?