Many are Called, Few are Chosen

For the past few weeks or so, I've been talking to one of my fellow college students, trying to cheer him up, keep him in school, and prevent him from sinking into depression. It all seemed like it was working, and I was happy knowing that I was once again fulfilling my role as a Guardian Angel of sorts, but then I learned yesterday that he was quitting. It struck me, hard, to think that everything I had worked to help him with was just... Now gone. Seemingly like wasted time, effort, and words lost on someone who left fear get the best over him.
I talked to him just before he left for his home town. I didn't try to reason with him, because at that point he had already filled out his paperwork. We chatted for the better part of that afternoon, reminiscing on all the stuff that happened last semester and what we going to happen this semester. It was fun, and we avoided that topic of his resignation until the final moments, when the awkwardness sets in and you've nothing left but to just bite the bullet.
He told me that he couldn't do it.
He told me that it was too stressful.
He told me that he was just getting depressed, to the point that he almost jumped in front of a train.
As much as I wanted to tell him that it was just a phase for the new semester, I could see the fear in his eyes. The instinct of running from that which you don't know, so I stayed my tongue, but that was short lived when he told me that he only stood out this long because of me. 
I.. I didn't know what to say... I didn't know whether I was feeling betrayed that I worked so hard for something fruitless, or that I was feeling happy, knowing I did my part to help him in his life. I said and expressed neither of the two, and instead just wished him good luck in life.
Many are called to a higher purpose in life. Few are chosen to actually complete it.