The personal confession made in verses 1-2 and in verses 5-6 makes it plain that the psalmist trusts in God alone. He is his only source of inner peace and security. A Christian should have this same confidence, and more: "Many are the high waves and dangerous are the storms, but we do not fear shipwreck: we are founded on rock. Although the sea may rage, the rock will not be destroyed. Although the waves may rise, the barque of Jesus will not be sunk. [...] Little of what the world sees as fearful troubles me. I laugh at the goods this world offers to me. I am not afraid of poverty, nor do I desire riches. I do not fear death, nor do I desire to go on living if that is not to my spiritual good" (St John Chrysostom, Sermo antequam iret in exilium).
The rest that the psalmist finds in God is found by the Christian reader of this psalm in Jesus Christ; he promised "rest for your souls" to those who followed him and took up his yoke (cf. Matthew 11:28-30).
This psalm arrangement is used in the Mass liturgy on the 8th Sunday in Ordinary Time, Year A.