In his mercy God has not forsaken sinful man. The punishments consequent upon sin, "pain in childbearing" and toil "in the sweat of your brow," also embody remedies that limit the damaging effects of sin. After the fall, marriage helps to overcome self-absorption, egoism, pursuit of one's own pleasure, and to open oneself to the other, to mutual aid and to self-giving.
-- CCC 1609
"Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven." There are no limits to the mercy of God, but anyone who deliberately refuses to accept his mercy by repenting, rejects the forgiveness of his sins and the salvation offered by the Holy Spirit. Such hardness of heart can lead to final impenitence and eternal loss.
-- CCC 1864