Paul wrote to the Corinthians to tell them about the thorn in his flesh: “So to keep me from becoming conceited because of the surpassing greatness of the revelations, a thorn was given me in the flesh, a messenger of Satan to harass me, to keep my from becoming conceited” (2 Cor. 12:7). Paul twice mentions not becoming conceited, or wrapped up in himself. This was why the messenger of Satan was harassing Paul.
Paul response was to beg God to remove this thorn: “Three times I pleaded with the Lord about this, that it should leave me. But he said to me, ‘My grace is sufficient for you, for my power is made perfect in weakness'” (vs. 8, 9). Grace means a gift, or having favor towards someone. It’s a leaning in to someone because you care about them.
We may never know exactly why God didn’t remove this “thorn” from Paul, but we know that God allowed Paul to be harassed by Satan and that God’s favor rested on Paul regardless of this harassment. It’s a reminder of the power of God’s grace in our times of weakness. God’s grace is abundant, and is sufficient!