Paul prayed three times. He did not cease pleading with the Lord until he received his answer—and it was not immediate healing!

Some believe Paul's thorn was a disease of his eyes, because of the above statement.

Paul was a vibrant individual, having many ideas and motives of his own. For this reason God kept Paul weak, pruned back. It is likely that Paul, for the most part, taught in fairly small home groups. Could he possibly have known that his letters, sometimes written from a feeling of frustration, would become holy Scripture?

We must mature to the point that we desire Christ to be magnified in us by our life or our death. We would love to come home to be with the Lord. Yet we are mature enough to bear fruit. But we have ideas and motives of our own and so God must keep our personality pruned back.

The suffering of pruning is certainly not that of wrath, and not exactly that of chastening. Rather it is a setting aside of us to God's holy purposes so, while our joy may be withheld for a season, people may see Christ through us as through a magnifying glass.

Again:

We are hard pressed on every side, but not crushed; perplexed, but not in despair; Persecuted, but not abandoned; struck down, but not destroyed. We always carry around in our body the death of Jesus, so the life of Jesus may also be revealed in our body. For we who are alive are always being given over to death for Jesus' sake, so his life may be revealed in our mortal body. (II Corinthians 4:8-11—NIV)

Paul was being given over to death continually in order to please Jesus and do the work that Jesus required of him. Because of his willingness to suffer under the hand of God in this manner, the Life of Christ has been revealed to countless numbers of people through the centuries of the Christian Era.

Who would not want to bear fruit to this extent? God chooses who His fruit-bearers shall be; and yet we are available for God's purposes only as long as we are willing to be pruned, frustrated, hard pressed, perplexed, persecuted, and struck down.

We see, therefore, that all people must suffer under the hand of God.

The rebels suffer the destructive wrath of God to a greater or lesser extent.

The Lord's sons suffer chastening until they are established, strengthened, and settled in Christ.

The Lord's mature saints suffer pruning that the excellency of the power may be of Christ and not of them.

When we refuse to suffer, always seeking how we can avoid unpleasantness, we lose our integrity. We forsake those who trust in us. We become people without principle.

An unprincipled person can never please God. He or she must be buried under tons of suffering if the cunning, evasive, self-seeking, manipulating, deceiving spirit is ever to be crushed and burned out of him or her. God will not have fellowship with those who are not utterly sincere.

There is something terribly sincere about Calvary! It is no place for the person who has learned to manipulate others by guileful deceits.

Let each believer accept the sufferings that come, praying always to the Lord for relief and joy, seeking His wisdom and strength in every situation, repenting when repentance is needed. He who endures to the end shall be saved and enter the joy of the Lord. (from Three Kinds of Divinely Appointed Suffering)