Psalms 16
David put his trust in God because:
v1-2: God is source of all blessings
v3-4: God is the object of worship
v5-6: God is the one who has given us an inheritance
v7-8: God is our teacher
v9-10: God is the source of joy
v11: God is the source of salvation

Psalms 16:11  Thou wilt shew me the path of life: in thy presence is fulness of joy; at thy right hand there are pleasures for evermore.