The anchor must be something out of ourselves: not our duties, nor our saintship, nor our walk with God, nor our evidences of the Spirit’s work within us, nor our strength of love — not any, nor all of these together! The anchor of a ship is something that lies without, and by being without secures it. That which quiets and assures the uneasy conscience and troubled soul of a sinner, is what he hears in the glad tidings. It is something said or shown to him by God. It is something that tells him, not of the feelings of his own heart, but of the heart of God. It is something that shows him the face of God, that he may read there, “God is love.” The work of Jesus, or rather Jesus Himself, in this way becomes the sure “anchor of the soul.” - Horatius Bonar
What a humbling way of expressing it - the anchor must be something out of ourselves. We can truly do nothing to soothe our souls on our own. Our surety must come from elsewhere.
That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us: Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil; Whither the forerunner is for us entered, even Jesus, made an high priest for ever after the order of Melchisedec. Hebrews 6:18-20