Survival of the fittest is the idea that species adapt and change by natural selection with the best suited mutations becoming dominant. -Charles Darwin, Origin of Species, 1869
The word 'fittest' referred to here are those animals which are the most suited to their environment, i.e. those which are best fitted with the characteristics and attributes that enable them to survive.
Our society takes this concept (which is flawed to begin with) and adds their sick twist to it... Our society says that the "better" you are physically, academically, etc... the better you are as a person.
While I was in my car this morning I heard someone talking about this concept on a local radio station. I have no idea who was talking, but something he said really stuck out to me. I can't recall it word for word, but essentially what he was saying was that society tells us that we must look a certain way, be talented in certain areas and be better than the people around us if we are ever going to do anything with our life. However, God simply doesn't see it this way at all. While the world may embrace the survival of the fittest approach, God looks to us with the survival of the faithful approach. God doesn't look at our worldly abilities, looks or knowledge - He searches our heart.
Samuel 16:7, "The Lord does not look at the things man looks at. Man looks at the outward appearance, but the Lord looks at the heart."