The last two posts (1,2) on Divine Mercy have as a central theme the Institution of Mercy. Mercy sanctifies the soul and protects from hell but this is a physical and institutional Mercy, not just a private confession of sins like what the Bible-only proponents preach. It is both. A Church that includes the gamut of relationships we can have with God, secret, private, communal, AND public, cannot be beyond the reach of an Omnipotent God. The sins are forgiven privately in the Sacrament of course but with more protection than just a private plea for mercy. To omit the institutional component of Holy Repentance leaves us more susceptible to worldly institutions, since the mercy granted had now become an objective truth. When Jesus forgave the paralytic, the world attacked Him for saying he was forgiven. So Jesus gave them a physical sign. He healed the paralytic which silenced His critics.
A personal plea to God for forgiveness can be believed, whether or not God granted it, but a sacramental act of forgiveness is real, whether or not the sinner believes it. It has become an objective truth. Part of a timeless deposit of mercy.
In case you have not noticed, the powers of this world live off the attacks and defamation of character of people. Take a politician running for office as an example. A political career can be completely destroyed by media defamation. Never mind that the attacks are always selective and for political purposes. No one of us is innocent. A Sacramental confession affords us additional public protection while protecting our privacy. Jesus offered His physical Nature for this: Body and Blood. If a Sacramental confessional will not save a political career it will at least manifest in some other physical way. As a witness to God’s Glory. Thy Kingdom Come. And phony institutions slowly go away.
Paralleling the private and Institutional component of Divine Mercy is the Church’s endorsement of private and Institutional prayers for Mercy. We privately pray to God in His Mercy. We also have prayers offered to us by the Church, said with the communion of faithful (physically present or not) to give our conversion a public dimension. An example is the Chaplet of Divine Mercy from the Roman rite and the Trisagion Prayers from the Orthodox tradition. Both have the following words in common, a witness to the work of the Holy Spirit:
Holy God! Holy Mighty One! Holy Immortal One! Have Mercy on us (and on the whole world). (said three times).