“I can do all things through Him who strengthens me.” (Philippians 4:13)
When Paul had a difficult personal situation (maybe a sickness), he prayed that God would take it away. But God answered him: “My grace is sufficient for you, for My power is made perfect in weakness” (2 Corinthians 12:9).
When you are weak or when you are suffering, the power of Christ can rest upon you in a special way. So if there is a disease raging, or if there is another problem in your life that overwhelms you, Christ can become visible in you in a way that does not happen when everything is fine. In every situation, you may know that God’s grace is sufficient.
Paul even said that he could do ‘all things’. That is not a boast, because he says he cannot do it through his own power, but that is is Jesus who gives him strength.
Moreover, when you read Philippians 4, you will notice that Paul is not talking about worldly success. He mentions that he can face hunger and poverty because Jesus gives him strength. The same is true when you are facing disease: nothing is too hard.
Jesus gives you strength. You do not need to be afraid.