How should a christian and act and what is he supposed to do

You're supposed to do the opposite of this. Pride is one of the worst sins we can commit. Beyond that, biblical meekness isn't being a weak doormat, it's having strength but having that strength under control.

Hypothetical question: let's say Russians start war with your country and their soldiers are about to execute your family. Would it be justifiable to kill them to protect your family?

gunpowdah

Generally, as others should say, perfection is the goal; following the Ten Commandments, Christ's instructions and the many exhortations in the Epistles are conducive to virtue. This much is obvious, however—the OP seems to want advice for particular circumstances. If he put in the effort to refine his questions it might help him.

Exactly, where did I said it isn't.
Hmm, you're not helping by not sourcing it, since its not true.
This is an oxymoron by itself.

The question is quite straightforward, sadly most people are ego driven even here.

Grow up mate.

Where did I claim to be better, I just want to better myself and so I asked this question. Though it seems to have hit some nerve.

How is it an oxymoron? I think your perception of what "strength" is is off base.