So, in general, we're talking about the interaction of human morality and the laws of nature. Why does doing good seem to lead naturally to bad outcomes?
Before going on, we should note that various thinkers have seen different fundamental "equilibria" in this respect. For example, Tolstoy (who thought marriage itself was immoral) saw sexual reproduction as a built-in safety valve given by God to the human race. In his view, as long as man had not yet become morally perfect, he would continue to propagate himself, thus giving the next generation another chance to get it right. Eventually, at the end of time, man would overcome all selfish desire and achieve moral perfection. Having achieved his reason for existing, he would then cease to exist. This is an odd and heretical view to say the least, but my reason for pointing it out is to show that what you or I or /pol/ might think about the fundamental laws of nature are not necessarily the whole picture.
Okay, now then.
First, it's not even clear that evolutionary laws do, in fact, favor immorality. At any rate, I don't think you can say that evolution in general favors immorality. You can see this because different animal species have different successful reproductive strategies. Some of these strategies would be considered immoral if pursued by humans, but some would be considered highly moral. If evolution is inherently directed toward favoring immorality, you'd expect to see no instances at all of, for example, animals mating for life. But we do. Therefore… etc.
Second, though, and more basic, is the philosophical approach you have to take to even arrive at a point where it makes sense to ask this question. Humans are not mere animals: we are rational animals. Evolutionary good is definitely a good for humans, but it is not the only or the most important good for us.
For humans, our rational faculties rule over our animal faculties, and our animal faculties are subservient to, and only exist for the sake of, our rational faculties. Therefore, in point of fact, those goods which pertain to our rational nature are far more basic to us as humans, and are far better for us, than goods which merely pertain to our animal nature, including the evolutionary good.
The conclusion is that to commit immorality to gain an evolutionary good, is to incur a harm greater than the good that was sought, because immorality, or sin, is in essence any act that contradicts right reason. So sin actually harms our rational nature, which in us is higher and more important than our animal nature. To pursue an animal good at the cost of a rational good is therefore to suffer a harm greater than the good sought.
So basically, the immoral don't in fact win in this life, but lose.
Aside from that fundamental point, there's also the point that God has not abandoned his servants entirely to the whims of nature and its sometimes cruel laws. Prayers are answered: see the Battle of Lepanto. God does intervene in history, and the entire Old Testament bears witness to this. But, in those (unfortunately not rare) cases where the good Christian man is in fact led to death by his own goodness, he is only following the road first trodden by his Master, who was sinless and yet submitted to suffer and die in a painful and humiliating execution under Rome. (And nowadays, who's in charge of Rome? What does that say about who actually wins in the end, even in this life?)