You see to me, science and faith are one. They are not mutually exclusive. Science should lead to faith, and faith should lead to science. Science cannot explain the important question of life: Why? And faith cannot explain the important question of life: How? One could argue that science explains the question of why with the simple fact that man is a biological organism. We are life and life exists for the same reason all other life exists — to create more life. And certainly faith can offer an explanation for the question of how. The world works the way it works because God ordained it. But both of these explanations are hollow.
To me, science and faith are opposites. Science is knowledge derived from evidence. Faith is a belief held in the absence of evidence. As to explanations, faith is not an explanation. A belief does not explain anything other than the ability of a person to believe things that can't be shown to exist. The only way you can explain anything is through knowledge, and faith does not lead to knowledge. Science does lead to knowledge. Even worse, beliefs can steer us away from knowledge.
Faith boils down to "I don't know, but it would be really cool if _____ were true, so I will believe that until someone finds the real answer."
Also, if you ask the question "why" you assume that there is a purpose. You first need to show that there is a purpose before asking for an explanation of that purpose. Science also can't explain why Leprechauns wear green, but then why would science need to explain this if no one can demonstrate that Leprechauns exist?
To say man is nothing more than an animal and biological organism is to deny empirical evidence to the contrary. For evidence, I offer the fact of Man ceasing to evolve.
Every person born has between 100 and 200 mutations. Man has not stopped evolving. Also, you assume that there is something man could be other than a natural biological organism. Do you have any empirical evidence that man can be something other than a natural biological organism?
First, we no longer practice random mating which is a prerequisite for natural selection.
You do know that sexual selection is part of natural selection, do you not?