“You keep him in perfect peace whose mind is stayed on you, because he trusts in you. Trust in the LORD forever, for the LORD GOD is an everlasting Rock.” (Is. 26:3-4)
The Lord is a Rock and he is everlasting. He is the self-existent One who is always the same. He is also the summum bonum, the supreme good who can always be trusted and who keeps his people in perfect peace when their minds are fastened on him in faith.
Is your mind on Him?