Our Scripture reading today is John 9:1-4.
Verse 3, "Jesus answered, Neither hath this man sinned, nor his parents: but that the works of God should be made manifest in him."
God is sovereign and His works in and through us are always best.  He allows challenges to come into our lives for our good and His glory.  The blind man in our text is not blind because He or his parents did some wicked, evil sin.  Remember, God always does everything with and on purpose.   Jesus makes it clear that this blindness was so God's power could be made known in him.  
Is there something in your life that you would like to remove?  Is there a physical difficulty?  Is there a co-worker that seems to always be critical of your work?  If you are a born again believer and love God, there is a promise to be reminded of in Romans 8:28.  "And we know that all things work together for good to them that love God, to them who are the called according to his purpose."  In addition, God promises to give us the grace we need to live in victory in spite of the challenges.  2 Corinthians 12:9, "And he said unto me, My grace is sufficient for thee: 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."