Why is it so hard to trust in the Lord? I can only speculate based on my own experience, but for me it is mostly me expecting something and not getting it. Does this mean I reject the Lord, absolutely not. I just need to understand that when my expectations are not met, it is for my own good.
Also, people do not trust God because He challenges us and we do not like it. God will never give you more than you can handle due to his love for us. He is not setting us up for failure, but He is going to push up to the edge. It is our choice to either rely upon Him and His ways or to rely upon ours and the worlds ways. I believe that He does this to make us stronger. When people are pushed to that point, they will rely upon what they know best. If you are the type of person that relies on the Lord, then we are pushed, we will give it to Him and ask Him for help. If we rely upon ourselves, then that is what we will turn too.
Another reason that people do not trust the Lord is that they do not believe. People are so willing to accept what man says even though there are flaws in their theories and there is no evidence that what man is saying is true. There is so much we do not know or understand, but we put forth a theory to explain it. However, instead of us questioning man and his theories, we question or reject God.
Finally, our lack of trusting in the Lord has to do with our inability to see God. It is easy to see man and to accept mans way, but it is really hard to take a leap of faith and trust in a supreme being that we do not see, touch, or hear. Mans way seems to make sense with our own thoughts and the logic man presents can seem very compelling. Even being a Christian, I at times think what if man is right, but quickly come back to reality and apologize to God for my actions.
I pray that if you are having trouble trusting the Lord, that you try to simply put God first and run from evil. I also encourage you to read scripture everyday and use it to resist the Devil. I know this all sounds simple, but the reality is, it is not. Trusting a being you cannot see, touch, and hear is a bit difficult and requires a leap of faith, but I pray that you will rethink you position and stop relying upon yourself. In Jesus name I pray for this, Amen!