I guess the story is really told from the perspective of the instructor, John Powell. And you are correct, there was no direct mention on why Tommy was looking for God. However, Tommy did say the following:
Oh, yes, very sick. I have cancer in both lungs. It's a matter of weeks....
Well, it could be worse.
Well, like being fifty and having no values or ideals, like being fifty and thinking that booze, seducing women, and making money are the real biggies' in life.
But of course! Thanks for pointing it out. Not believing and having no values nor ideals are two separate things. This makes the story suspect because it is associating atheism with *vices* when it's not really necessary. I searched for it in the net. Although Mr. Powell is still alive to confirm the story to be "true", unfortunately Tommy is no longer here to dispute it. For the sake of discussion, let's asume the story is true. But first, we must admit that one can be a believer, be fifty and think that booze, seducing women, and making money are the real biggies' in life. This is so obvious now even as we speak.
As for meaning, one can be a non-believer and still find meaning (think Sartre here). Meaning is not the monopoly of (Christian) believers.
On Kant (so far I have only read his introduction to his philosophy Logic so I may be off the track here. This is how I'd put it using my own understanding.), if there must be an absolute code of morality - The Right Thing (tm) - then even a god must be governed by this absolute code. For example, if murder in any context is absolutely unjustifiable, then even god will have to abide by it. But if god is exempted, i.e., if a god sanctions murder (e.g., god of the Old Testament) and if this is justifiable simply because it's god (I have heard this often enough that even genocide is justified if it's god who is doing/ordering it) then there will be no absolute code of morality because god must be following a separate rule (murder is okay), while humans follow another set (murder is unjustifiable). But.... if there must be just one absolute set of values (e.g., murder is in any time and all cases is absolutely unjustifiable), then this absolute must be above both gods and humans alike. That god must abide by this same absolute code, it then follows that the same absolute code can and must be existing independently of the gods. Therefore you don't need a god in order to have absolute set of values. OTOH, if god is required in order to define this absolute moral code, again morality becomes arbitrary because god can say murder is a virtuous act and because it was god who said so, it becomes absolutely the right thing to do, magically. If, as you say, human minds can grasp these supposed absolute code of morality, why do we *have* cultural relativism? And why is morality evolving? Whereas slavery and race segregation used to be acceptable in the southern states, they are not now? And very recently, the Philippine congress moved to abolish capital punishment whereas it was re-instituted as lately as 1993?.
I personally believe that people do the right thing because they think it's the Right Thing to do given the context or circumstances. Man is capable of weighing the quality and consequences of his actions and act morally. Even if there is indeed an absolute code of morality, it still doesn't follow that there must be a god who put it there (Occam's Razor). It's just there. Now, Tommy could have been a better person than he already was without having to believe. This reminds me of this challenge made by one fundamentalist Christian website on whether turning to atheism could make an ex-believer a better person for example by making him stop beating his wife. The idea being, that there have been atheists who have lead sinful lives but who have stopped beating his wife after turning Christian. The question that should have been asked in the first (Christian) case was pointed out by one visitor is that, why despite being a Christian would one would lead *sinful* ways and want to beat his wife?
I apologize if I seem to be out of context. This being under the inspirational and spiritual. I just think that if a story should inspire us or uplift our "spirits", it must not come at the expense of other religion or in this case, non-belief. Just in case you are wondering, I do have very strong opinion against religion (not on belief itself) and its effects to our society but I put it somewhere else. For me, mere belief and non-belief are not ethical systems by themselves.