Every life has difficulties.
It may be a difficult marriage, chronic pain, depression, painful childhood memories, past mistakes, or emotional pain. Maybe you have begged God to take it away, but it's still there. Paul asked the Lord three times to take away his thorn in the flesh. Christ prayed the night before He was crucified, My Father, if it is possible let this cup pass from me. Even in their willingness to do God's will there was an expressed desire that God take the hard thing away.