Trust?

Sometimes I wonder why it is so hard to trust in God. I know He would never do anything to hurt me, yet I still don't always trust. As I sit here waiting, I am thinking about a bunch of stuff, and one person I am thinking about is my best bud Caleb Dominguez. He is one of the most amazing people I know, and I am so blessed to have him in my life. Unfortunately right now he is battling Leukemia. THIS SUCKS! There are so many times I ask God, "Why is Caleb having to go through this?" All he desires to do is serve the Lord, and yet his has this horrible disease. I just got done watching a video about Caleb on his website:Why is it so hard to trust in the Lord? I know that He has everything in control and He would (http://www.calebsmountain.org) And when it was finished, God told me...Stacee you don't need to know why Caleb is going through this. All you need to do is trust me.
Caleb is serving God to the best of his ability right now. Even in the past 3 weeks that he has been in the hospital, he has been a blessing and a witness to those who are helping him out. He is constantly in the word, and constantly talking to people about his faith. It seems like Caleb has more trust in God with this situation right now than I do, AND IT IS HAPPENING TO HIM!
I know that God has a plan and purpose for everything, but right now I am struggling with trusting Him with it.
I thank the Lord and pray daily for Caleb. I know that God will see us all through this valley.