Do you struggle to believe? The Bible says that unbelief is a sin (all unrighteousness is a sin). Having unbelief in your heart denies the goodness of God.

“Beware, brethren, lest there be in any of you an evil heart of unbelief in departing from the living God;” Hebrews 3:12 

Cry out, “Lord, I believe; help my unbelief!” Mark 9:24