St Paul makes much of weakness.
In 1 Cor 1:25 he makes the famous statement "the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength." This verse comes at the end of a short section on how the wisdom of God seems to be foolishness to men.
Again, in 2 Cor 16-29, St Paul enumerates the times when he was persecuted, beaten, and suffered at the hands of men and in natural hardships. In this he explains that these show his weakness. He does not fight them but endures them. What is extraordinary is that he then boasts of his weakness (cf v.30).
Finally he ties this to Christ in 2 Cor 13:4, who "was crucified out of weakness, but he lives by the power of God. So also we are weak in him, but toward you we shall live with him by the power of God."
There is a paradoxical relationship between strength and weakness in St Paul's letters. At first glance, it seems as if it were a simple comparison between the human and the divine. The divine is just a bigger version of the human. Hence the weakness of God is stronger than the strength of man. So then in Paul's list of hardships, he is weak, The list of hardships continue to demonstrate this weakness, but why would he then boast of them? Christ dies in weakness? Where is the power of God in that?
One may ask if a Christian should simply expect no earthly rescue by God. It's just that God is really powerful and we are not. Christians are not allowed to fight back so we just have to suck it up and take it. Even Jesus himself had to simply let himself be killed.
I will suggest that this weakness is not something inflicted upon Paul but an impenetrable shield for his defense. The reason speaks to how the devil works. To quote Tolkien, "the Shadow can only mock, it cannot make." Evil corrupts. All sin is a corruption of something good. Worldly power, therefore, is a handle by which the devil can grasp to use against us.
What then is our protection against this corruption? Weakness. Weakness is the only thing that evil cannot corrupt. It has nothing to grasp us by. This weakness is related to kenosis, the self-emptying St Paul speaks of in Philippians 2:7. Self-emptying means ridding ourselves of pride, it means a true humility, a realization that to God alone belongs the victory, even when furthered by our own efforts. Most importantly, it is a radical dependence upon God and his providence.
This radical dependence appears from the outside to be weakness, but upon it we can safely rely for invincible protection.