Trust in the Lord with all your heart, and do not rely on your own understanding; think about Him in all your ways, and He will guide you on the right paths.
Proverbs 3:5-6 HCSB
To fully trust in the Lord is to show the faith of a child; we must do it, we are commanded to do it. If we put God at the forethought of all of our actions and thoughts, our lives would be immensely better; less stress, less worries, less negativity, and much more joy. To worry is to go against God‘s will because you are saying you don’t trust Him to handle the situation, to go against His will is to sin, so to worry about a situation is a sin because you are not trusting the Lord.
We must trust in the Lord with ALL of our hearts; God will not lead you astray, but the devil will.