Some think our trials come from God to keep us humble, etc. They will often quote 2 Corinthians 12:7-9 as their proof text in this regard, so let's look at this together.

2 Corinthians 12:7 And lest I should be exalted above measure through the abundance of the revelations, there was given to me a thorn in the flesh, the messenger of Satan to buffet me, lest I should be exalted above measure. 8 For this thing I besought the Lord three times, that it might depart from me. 9 And he said unto me, My grace is sufficient for you: for my strength is made perfect in weakness. Most gladly therefore will I rather glory in my infirmities, that the power of Christ may rest upon me.

Because of this text some believe that it's God who puts trials on Christians in order to keep us humble and that this 'thorn in the flesh' that Paul suffered from was one such trial. In this case not realising that it was God who gave him the problem, the understanding is that Paul prayed three times for it to be removed. Finally according to this belief God had to tell him in so many words that he was stuck with this 'thorn' because otherwise he might develop pride from having had God give him all those revelations.

So in this scenario if we plead with God three times to remove some sickness from us or someone else and He doesn't,  then the likelihood is that God has given it to us/them to teach  some needed lesson! It could be pride as in the 'case' of Paul or some other sin that is crouching at the door and God's grace will keep us from committing it while we live with the trial for the rest of our lives.

So we follow God through coersion and under duress rather than love! This seems a rather blunt instrument for a loving God to use to teach His children lessons, and not one that we would consider as an example for men to follow! If men gave their children diseases to teach them lessons we'd expect the authorities to throw them in jail, not commend them on wise action!

I rather think that the text gives the correct answer when it says that the thorn was a 'messenger from satan', as I find that usually the bible explains itself quite well!

There is nothing wrong with being elevated/exalted, if it's done by God! See what God says in Mat_23:12.

Matthew 23:12 And whosoever shall exalt himself shall be abased; and he that shall humble himself shall be exalted.

And, Jesus told the disciples that whatever they said to a problem would be done; but THEY had to say it!

Mark 11:23 Whoever says to this mountain, 'Be taken up and thrown into the sea,' and does not doubt in his heart, but believes that what he says will come to pass, it will be done for him. Therefore I tell you, whatever you ask in prayer, believe that you have received it, and it will be yours.

Of course as we know Paul wasn't there at the time so He was carrying on with the Old Covenant system of "telling God about the mountain", instead of 'telling the mountain about God!"

Jesus had to point out to Paul that His Grace was sufficient for Paul to cope with any trial or tribulation or remove any disease or ailment, when Paul commanded it in Jesus' name.

We have the authority, just like Peter, John, Paul and the other disciples did, given to us by Jesus!

Later we know Paul was so full of grace that even items of his clothing when sent to the sick would bring healing! And if we need more grace God will supply it to those who draw close to Him. (James 4:6)

What a good God we worship!