But the Lord said unto him, Go thy way: for he is a chosen vessel unto me, to bear my name before the Gentiles, and kings, and the children of Israel:

And base things of the world, and things which are despised, hath God chosen, yea, and things which are not, to bring to nought things that are:

COMMENTARY

But the Lord said unto him, Go thy way: for he is a chosen vessel unto me
When Ananias protested going to bless Saul, God informed him that the man was a “chosen vessel,” and indeed one can see how Saul would be considered a powerful asset to God’s cause. He was intelligent, effective, and tireless in his pursuits, even if those pursuits were momentarily pointed in the wrong direction.
And yet the man that Ananias found in need of a blessing must have been a far cry from the self-powerful tyrant that he had been afraid of. For at this point Saul had had his preconceptions of God shattered, been rebuked by the true Lord, completely blinded, and left to wallow three days and three nights without either food or water. In short, God had broken the vessel that Saul once was, and the “chosen vessel” that he referred to, was going to be a new creature. One that would be called Paul.

And base things of the world, and things which are despised, hath God chosen
Paul himself later avowed that God did His work with the base and the despised, the humbled and the broken. He spoke of how the “foolishness” of God was greater than the wisdom of man (1 Corinthians 1: 25). He knew this because he had been directly at the receiving end of it! While still wise in the ways of the world, he had been broken by the same Savior he had voraciously denied. And now he had thrown in his lot with those that he once considered “base and despised.”
In short, Saul, the brittle vessel could not have done anything for God, only Paul, the humbled clay could. It has been said that God does not call the qualified, he qualifies the called. He has no need for our power, only for our will.