Strength is born of adversity. One should strive for personal strength (be it physical, intellectual, etc.) for what purpose however? For survival of course, pure and unemotional. The instinct and ability to survive perpetuates itself in this way.
So why must the weak be purged? Because they weaken all who depend upon them, all of the community in which they live. Not only this, but praying on the weak only makes the strong stronger. Such is the case when the stronger of two chicks pushes the other from the birds next to its death... the weak is eliminated, and the strong becomes stronger. The family of birds as a whole is better off.
But is the chick evil? Does it consciously feel malice, or hatred for the sibling it killed? No. Does it feel remorse? No. It may be a selfish act, but one of self preservation. Without emotions such as malice, an act of self preservation (or even self advancement) cannot be considered evil.
Now lets give the 'beings' under consideration emotion, something you claim to be devoid of. Now we have higher reasoning, complex societies, and time to concentrate on things other than survival. What is considered 'strong' is such a society?

Strength is still born of adversity. But malice, compassion, and countless other dichotomous emotions come into play. Does the murderer who targets the poor and helpless bring strength to himself? No, he weakens the society which in turn strikes back at him. Is the pacifist poet a weak link in the society? Certainly not, if his work brings enlightenment, encourages thought, or enspires others to greatness.
What it boils down to is this - strength is measured by survival. Evil is necessary to prevent stagnation, to spur on society to achieve more. Greed is an excellent example - it is the greatest motivator, because it directly relates to survivability. Good is necessary to bind a society together, to allow new, fragile seeds to blossom to full strength without being crushed prematurely. Each works in harmony, the conflict of the two merely a struggle to maintain the carefull balance that must exsist.

Oh, one last thing - the church does not 'strive for weakness' as you put it. To do so would be to strive for its own extinction, and to go against the very nature of mortality. If this were the case, there would be no church, or at least no need for outsiders to strive for its downfall.



Penned by my hand on the 13th of Valnuary, in the year 231 AF.