I was talking one day to someone about how God uses people that others have given up on. After I stopped and really thought about it, that includes many of the so called "heros" of the Old Testament and New. There is a section of scripture where it says,
"For consider your calling, brethren, that there were not many wise according to the flesh, not many mighty, not many noble; but God has chosen the foolish things of the world to shame the wise, and god has chosen the weak things of the world to shame the things which are strong, and the base things of the world and the despised, God has chosen, the things that are not, that He might nullfiy the things that are, that no man should boast before God." 1 Corinthians 1:26-29, NASV
And when you do a survey of scripture you see that this is the truth. Gideon for example describes hmself in Judges 6:15 as being from the least family in Manasseh and the youngest of his father's household. And the time when the angel appeared to Gideon he was beating out the wheat to try and save it from raiding Philistines. Another example would be Moses Exodus 3:11. We think of Moses as really great, but do you know he killed a man and hid him in the sand Exodus 2:12. Or what about David, he was responsible for the death of Uriah and adultery with Bathsheba 2 Samuel 11. Or what about Peter who denied that he even knew Jesus John 18:25-27.
I think what that passage in 1 Corinthians above tells us that God intentionally choses the things of this world that are not that He might alone get the glory for what happens. He wants people who are leaning on Him and trusting Him and depending on Him in order for something good to happen. So that when it does He alone will get the credit for it. Need more proof, look at the disciples themselves.
Even up to the Lord's Supper itself the disciples had been arguing over who was the greatest of them Luke 22:24. They were consumed often times by petty arguments. Just as the church is often today. That is why on the night that he was betrayed Jesus got up from his seat and grabbed a wash basin and washed the disciples feet. They had a pride problem that they needed to be cured of before God could do anything good through them.
I think this is why God was able to use Paul for as long as he did. He was always aware of his shortcomings and faults. And if there was a problem with pride that seemed to evaporate when God gave him what is called the thorn in the flesh, which we don't exactly know what that was. When Paul asked for it to be removed in 2 Corinthians 12:9 the Lord said this and if it is true for Paul it is true also for us.
"My grace is sufficient for you, for power is perfected in weakness."
In response Paul was able to say,
"Most gladly, therefore, I will rather boast abot my weaknesses, that the power of Christ may dwell in me. Therefore I am well content with weaknesses, with insults, with distresses, with persecutions, with difficulties, for Christ's sake for when I am weak, then I am strong." 2 Corinthians 12:9-10