Basically the author is saying that although he believed that his Christian faith was solid, he got the wind so knocked out of him by the senseless death of his mentor that, within another year or so, he had "stopped" being a Christian.
I don't know this person, so I can't guess how deep his faith went, or the amount of grief he had to deal with.
But if the same logic applied to all Christian believers, then there would have been no Christian believers. Ever. Because that's exactly what happened on Good Friday.
Of course the disciples had the Resurrection to boost them up, a few days later, just as we have the promise of eternal life. But all the same, would they ever forget the grief, failure, abandonment, betrayal that that Friday meant? Yes, they saw Jesus alive--but did that end all their questions about the God who allowed His Son to suffer?
If the same logic applied to me, my faith would probably either have been still-born...or killed off as well. In some ways, it has died, more than once, through sin, stupidity, apathy, failure, disappointment, discouragement, betrayal. (Sometimes other people's, sometimes mine.) Every time we've had to make the decision to leave a church, some of my belief in God's people has been shaken. I've seen Christians I trusted charged with criminal acts. I've known others who should have been and weren't--which was worse. I've seen Christian marriages, those that were an example to me, fall apart because of addictions; and ministries break apart over greed and power struggles. I've often felt, like the author of the essay, that if we lose whatever or whoever most symbolizes Christ to us, then is there a point to continuing?
It seems that the body of Christ, once again, failed to see, to offer support and help where it was most needed...or maybe it was there, and this grieving Christian just didn't see it or couldn't receive it. I don't know. But even when the last friend has gone, the last mentor or reason to stay in the church has been taken--each Christian is still on his or her own journey. Whether with welcome (or unwelcome) company, or alone for a stretch, the road is our own. If that sounds like something from The Pilgrim's Progress, that's exactly what's on my mind, because that "Christian" had a mentor and best friend senselessly taken from him as well...and yet he continued on, I think, in part, to honour the memory of one he had loved. And for a much greater reason: because it was his journey.
They therefore brought [Faithful] out to do with him according to their law; and first they scourged him, they they buffeted him, then they lanced his flesh with knives; after that, they stoned him with stones, then pricked him with their swords, and last of all, they burned him to ashes at the stake. Thus came Faithful to his end.
Now, I saw that there stood behind the multitude a chariot and a couple of horses waiting for Faithful, who (so soon as his adversaries had dispatched him) was taken up into it, and straightway was carried up through the clouds with sound of trumpet the nearest way to the Celestial Gate. But as for Christian, he had some respite, and was remanded back to prison; so he there remained for a space. But He who overrules all things, having the power of their rage in His own hand, so wrought it about that Christian for that time escaped them, and went his way. And as he went, he sang, saying:
"Well, Faithful, thou has faithfully professed
Unto thy Lord, with whom thou shalt be blest.
When faithless ones, with all their vain delights,
Are crying out under their hellish plights.
Sing, Faithful, sing, and let thy name survive;
For, though they killed thee, thou art yet alive."