When we give our life to christ that's when doubt now comes in and this happens to people that thought God is a magician because the trust is not there and the doubt of am I doing the right thing will set in and this will only kill your faith and you will lose your way.
1 Peter 5:7
Casting all your care upon him; for he careth for you.
Somebody approached me in church few years ago talking about how rich he was when he was in the world, now things are bad with him at that particular time. What surprised was what he said "am I even doing the right thing following God because all is his friends are better now".
As Christians what Satan attacks first is our mind and if is successful that when doubt comes in and from there if care is not taken we go back to sin. What are you going through? God is sufficient for us all you can cast all your problems to him.
Don't let doubt take you away from God,God loves us all and he is capable of solving all of our problems because nothing is too big for him and all we have to do is to wait for our time. Your problem is not bigger than God,keep praying and trust in the lord.
Thanks for your time.