By the hand of Grace. Rising above our weaknesses.

When the Lord chooses a man to do a specific task in line with devine purpose, most times not one has the skills, abilities and competencies required.Even Moses, the Lord's servant was of a stammering tongue and yet, the Lord had chosen him to lead his people. 

In Exodus 4, Moses complained to the Lord that he wasnt the man for the job. Infact the bible says that the anger of the Lord rose against him when he insisted on his weekness.

And Moses said to the Lord, O Lord, I am not eloquent or a man of words, neither before nor since You have spoken to Your servant; for I am slow of speech and have a heavy and awkward tongue. And the Lord said to him, Who has made man's mouth? Or who makes the dumb, or the deaf, or the seeing, or the blind? Is it not I, the Lord? Now therefore go, and I will be with your mouth and will teach you what you shall say.(Exo 4:10-12 )

Moses experienced the strengthening of the Lord in his weaknesses and God would fill up that which he was lacking to  fulfil this mission. In Jeremiah 1:9, we see the Lord putting forth his hand and touching the lips of the prophet, to put his words in his mouth when he was worried he could was too young to speak. 

Just look at your own calling, believers; not many [of you were considered] wise according to human standards, not many powerful or influential, not many of high and noble birth. (1 Cor 1:26)

God has always called men with weaknesses. If you are called, there must be potentially a weakness you are dealing with either at a personal level, or according to world standards. 

As for Paul in 2 Cor 2:19, even so the Lord made it clear that His Strength would be made perfect in Paul's weakness. How? That his grace was sufficient. With this understanding, he even resolved to boast in his weaknesses which would then cause the power of Christ to settle on him. 

Understanding this therefore, our mindset changes in regards to weaknesses and instead of looking at them as challenges, we look at them as our sources of power. We understand that we are able to do that which is far above our means, far above our energy, our intellect simply because the hand of grace is with us. 

As the scripture says, 

Not that we are sufficient of ourselves to think any thing as of ourselves; but our sufficiency is of God; (2Co 3:5)