I work with children who are 2-5 years old. After Frozen 2 came out I asked the kids if they thought that when they are older everything will make sense. The answer was a resounding yes. It's true that as we grow we gain more knowledge and more things make sense, but not everything. There's a reason that not everything makes sense. If everything made sense then we would be God. God knows everything and it all makes sense to him because he has understanding of everything. Meanwhile, we don't understand as much because of sin. We ask why bad things happen. We don't understand all of the things God let's happen.
In Luke 13 we find the event of feet washing. Jesus does what the lowest servant was to do. Jesus washed his disciples' feet. Peter questions Jesus wondering why he would do such a thing. In verse 7 Jesus replies: "You do not realize now what I am doing, but later you will understand." Though Jesus was talking about feet washing it makes me think about other things we don't understand. We may not understand why evil seems to be winning in the world. We don't understand why good people and young people are taken too soon. Sometimes we may even wonder if God has a plan or if he cares. Jesus showed that he cares in many ways but washing his disciples' feet was one of them. He took on the role of servant to show his love to others. That's what we are called to do as well.
So, what are we to do when things don't make sense? We are to trust God. He has not left us or forsaken us. He's still here. He cares and has plans for us.