Galatians 6:11

11 See with what large letters I am writing with my own hand. [Mark carefully these closing words of mine.]

Remember that when Paul was in Galatia he was very sick.

And [yet] although my physical condition was [such] a trial to you, you did not regard it with contempt, or scorn and loathe and reject me; but you received me as an angel of God, [even] as Christ Jesus [Himself]! Galatians 4:14

We can also see in scripture that Timothy also seemed to be sick a lot.

Drink water no longer exclusively, but use a little wine for the sake of your stomach and your frequent illnesses. 1 Timothy 5:23

So many of us believe, and falsely believe, that if we are sick it means that we have done something wrong, or that we lack faith. 

So for the sake of Christ, I am well pleased and take pleasure in infirmities, insults, hardships, persecutions, perplexities and distresses; for when I am weak [in human strength], then am I [truly] strong (able, powerful in divine strength). 2 Corinthians 12:10

When we are sick, our flesh is weakened, yet that allows our Father’s strength to be great within us. Paul and Timothy were used by our Father to heal people all of the time. They were used wonderfully by our Father, even though they were sickly. Paul asked our Father to remove the thorn in his and our Father told him no.

And to keep me from being puffed up and too much elated by the exceeding greatness (preeminence) of these revelations, there was given me a thorn (a splinter) in the flesh, a messenger of Satan, to rack and buffet and harass me, to keep me from being excessively exalted. Three times I called upon the Lord and besought [Him] about this and begged that it might depart from me; But He said to me, My grace (My favor and loving-kindness and mercy) is enough for you [sufficient against any danger and enables you to bear the trouble manfully]; for My strength and power are made perfect (fulfilled and completed) and show themselves most effective in [your] weakness. Therefore, I will all the more gladly glory in my weaknesses and infirmities, that the strength and power of Christ (the Messiah) may rest (yes, may pitch a tent over and dwell) upon me! 2 Corinthians 12:7-9

Our Father will use us lay hands on the sick and they will recover, even if we are sick. Look, He used Paul to do that all of the time. The Truth is that there are times when our Father will allow our flesh to be sick and that will cause us to be used by Him in even a greater capacity. Our Father’s ways and His Grace are directed primarily towards our spirits, which are eternal. For our spirits to be strong, our flesh has to become weak. This is why He causes us to walk by faith and not by sight, 2 Corinthians 5:7.