Psalm 55:22.

Cast Your Cares on the Lord and He Will Sustain You.
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ADDED: For the formal:

22 Cast thy burden upon the Lord, and he shall sustain thee: he shall never suffer the righteous to be moved. 23 But thou, O God, shalt bring them down into the pit of destruction: bloody and deceitful men shall not live out half their days; but I will trust in thee.

For the less formal:

Cast all your anxiety on Him, because He cares for you.