The secret of the Lord is with those who fear Him, And He will show them His covenant. Psalms 25:14
Says John MacArthur, “The “secret” could also be translated as “counsel” or intimate personal communion (Job 29:4, Ps. 55:14, Prov 3:22).” This counsel is made available only to those who fear God.
David sees his iniquity here as “great”. He has piled up an immoveable mountain of sin and regret which is why he pleads for God to remember His “tender mercies and loving kindness.”
Maturing in Christ brings a heightened awareness of personal transgression. This leads the contrite to a consistent application and reminder of God’s pardoning grace. My sin is great and has wounded me deeply but I’m reminded that those who have “suffered in the flesh have ceased from sin” (1 Pet 4:1).
We are not sinless as Christians, but we will sin less and less until at last we see Christ in all His glory. For now, the HOPE of glory will do.