How do you find truth?
Adherence to internal consistency, logic and consistency with reality, empiricism. It is the best we know of when it comes to knowing truths, if truth is to mean anything at all that is.
What is the role of evolution?
Efficiency, resistance, complexity.
What is going to happen to humankind?
A lot, I think we will be here for a good while, but chances are that some nut case will make us history.