Once mankind was put out of Paradise due to original sin, two impediments to his return existed: (1) he needed redemption which was supplied by Jesus on the Cross, (2) he needed sanctification which is supplied by man in this life. Is this right?
Your terminology and theology need a bit of refinement. You are correct in asserting that we were put out of Paradise due to Original Sin. You are also correct in saying that Jesus has redeemed us, that is, he has purchased our salvation, by his once and for all perfect sacrifice on the cross.
However, man, does not supply sanctification. Only God can sanctify so as to save us. It is true, that works do accompany the gift of our faith. But these works are not so much the source of our sanctification, as the result of it. Our works are God's gift to us. Scripture says, “For we are God’s workmanship, created in Christ Jesus unto good works, which God prepared in advance for us to do” (Ephesians 2:10). So, for us, all is gift, all is grace. Sanctification is a work of God in which we cooperate, and our merits are due to grace, not to our nature (Trent, VI, cap. xvi).
Finally, it is not God's will that we merely return to some earthly paradise. Rather, in his immense love, and despite our grievous fall, God has now willed to open heaven itself to us. Thus our redeemed state is greater than even our original state before the fall.
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