How many times in your walk with Jesus, have you questioned the events that have happened in your day to day living? I can't even count how many. I'm in my late 50's and have been a believer since I was 12. There are too many to count for me but as much as I know that my God exists, and I've seen God answer the most seemingly impossible prayer requests over my lifetime, there are still questions that do arise.
What is most important is knowing that you know. Like a small 5 year old that will believe anything their parent tells them because they know that their Mom or Dad is smart and loves them. They don't understand the meaning of love and trust, but their inner being and their heart knows better. God created us to be able to trust Him with faith. Believing that He knows better than we could ever know because He knows the future and He wants the best for us. He does not force us to believe though. He created us to decide what we wanted to do and never wanted to force someone to love or trust Him. That is what faith is all about. When we can't see the future, or understand what in the world is going on in our life, we will know that God will work it out.
An unbeliever will not see things the same way. They usually will question why God would allow people to suffer. "If God is so good, how could he allow bad things to happen?" is usually the big question. This is a crazy world with evil in it. God created us knowing that Adam would sin but then God would send His only son Jesus Christ, to pay for our sin on the cross. In the mean time, there is still evil because not everyone in the world chooses to do good. We, as believers, fall everyday too. I still believe that God is good and He planned it so we would be able to choose Him and want to be close to Him. Life is not perfect and just because we believe in God doesn't mean we will never go through difficult times. It means we will have HIM to comfort and support while we go through our trials.
Think about it.... as a believer who has gone through some trials in life, haven't you learned from them? Did you grow spiritually in your understanding of what God was trying to teach you? I did. I do every single time. Even now, while I'm in the trial of my life, I have learned to trust God, knowing that His Grace is sufficient for me and the more I pray and seek Him, He reveals Himself in the most amazing ways. God always has a plan who knows the future, knows how many hairs are on our head and loves us unconditionally. Trusting God comes from going through difficult and pain full times coming out on the other end victoriously.
Read Philippians 4:6-7