The Original post asked ...
I gave an answer for that. Now you want to know what happens in regeneration?
James Cardinal Gibbons wrote, over a hundred years ago, that
The grace of God is that supernatural assistance which He imparts to us, through the merits of Jesus Christ, for our salvation. It is called supernatural, because no one by his own natural ability can acquire it.
Without Divine grace we can neither conceive nor accomplish anything for the sanctification of our souls. "Not that we are sufficient," says the Apostle,
"to think anything of ourselves, as of ourselves; but our sufficiency is from God."[II. Cor. iii. 5.]
"For it is God who worketh in you, both to will and to accomplish"[Phil. ii. 13.]
anything conducive to your salvation. "Without Me," says our Lord, "you can do nothing."[John xv. 5.]
But in order that Divine grace may effectually aid us we must co-operate with it, or at least we must not resist it.
The grace of God is obtained chiefly by prayer and the Sacraments.
A Sacrament is a visible sign instituted by Christ by which grace is conveyed to our souls. Three things are necessary to constitute a Sacrament, viz.--a visible sign, invisible grace and the institution by our Lord Jesus Christ.
Thus, in the Sacrament of Baptism, there is the outward sign, which consists in the pouring of water and in the formula of words which are then pronounced; the interior grace or sanctification which is imparted to the soul: "Be baptised, ... and you shall receive the gift of the Holy Ghost;"[Acts ii. 38.] and the ordinance of Jesus Christ, who said: "Teach all nations, baptising them in the name of the Father, and of the Son, and of the Holy Ghost."[Matt. xxviii. 19.]
Baptism and regeneration are linked according to the scriptures. So the Catechism of the Catholic Church says that
I. One Baptism for the Forgiveness of Sins
977 Our Lord tied the forgiveness of sins to faith and Baptism: "Go into all the world and preach the gospel to the whole creation. He who believes and is baptised will be saved."[SUP]519 [/SUP]Baptism is the first and chief sacrament of forgiveness of sins because it unites us with Christ, who died for our sins and rose for our justification, so that "we too might walk in newness of life."[SUP]520[/SUP]
978 "When we made our first profession of faith while receiving the holy Baptism that cleansed us, the forgiveness we received then was so full and complete that there remained in us absolutely nothing left to efface, neither original sin nor offences committed by our own will, nor was there left any penalty to suffer in order to expiate them.... Yet the grace of Baptism delivers no one from all the weakness of nature. On the contrary, we must still combat the movements of concupiscence that never cease leading us into evil "[SUP]521[/SUP]
979 In this battle against our inclination towards evil, who could be brave and watchful enough to escape every wound of sin? "If the Church has the power to forgive sins, then Baptism cannot be her only means of using the keys of the Kingdom of heaven received from Jesus Christ. the Church must be able to forgive all penitents their offences, even if they should sin until the last moment of their lives."[SUP]522[/SUP]
980 It is through the sacrament of Penance that the baptised can be reconciled with God and with the Church:Penance has rightly been called by the holy Fathers "a laborious kind of baptism." This sacrament of Penance is necessary for salvation for those who have fallen after Baptism, just as Baptism is necessary for salvation for those who have not yet been reborn.[SUP]523[/SUP]
519 ⇒ Mk 16:15-16.
520 ⇒ Rom 6:4; Cf. ⇒ 4:25.
521 Roman Catechism I, 11,3.
522 Roman Catechism I, 11,4.
523 Council of Trent (1551): DS 1672; Cf. St. Gregory of Nazianzus, Oratio 39,17: PG 36,356.
Thus what happens in regeneration is that one is baptised and one's sins are washed away and one becomes a member of the church of the Lord Jesus Christ.
Now, what has regeneration to do with one's prayers for the lost?