Can every sin be forgiven?

[Jkuehn]

Some sins seem so grave that it seems as though they can never be forgiven. Are humans limited enough in the good and evil that they do that they can be forgiven by God at any point, even after committing the most grave moral sin? Since God loves everyone including sinners, how does he deal with the evil? Can a Catholic who believes in Christ but does despicable evil still go to heaven after purgatory, or would they go straight to hell? Does that change if they asked for forgiveness?

 

[Vico]

Some sins seem so grave that it seems as though they can never be forgiven. Are humans limited enough in the good and evil that they do that they can be forgiven by God at any point, even after committing the most grave moral sin? Since God loves everyone including sinners, how does he deal with the evil? Can a Catholic who believes in Christ but does despicable evil still go to heaven after purgatory, or would they go straight to hell? Does that change if they asked for forgiveness?

The only thing that can prevent forgiveness is rejection of forgiveness.

Catechism

1263 By Baptism all sins are forgiven, original sin and all personal sins, as well as all punishment for sin.66 In those who have been reborn nothing remains that would impede their entry into the Kingdom of God, neither Adam’s sin, nor personal sin, nor the consequences of sin, the gravest of which is separation from God.

The sacrament of forgiveness

1446 Christ instituted the sacrament of Penance for all sinful members of his Church: above all for those who, since Baptism, have fallen into grave sin, and have thus lost their baptismal grace and wounded ecclesial communion. It is to them that the sacrament of Penance offers a new possibility to convert and to recover the grace of justification. The Fathers of the Church present this sacrament as "the second plank [of salvation] after the shipwreck which is the loss of grace."47

1864 "Therefore I tell you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven."136 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.137 Such hardness of heart can lead to final impenitence and eternal loss.

 

[AugustTherese]

Final un-repentance, like @(name removed by moderator) mentioned.

 

[Kei]

If he repents of his terrible evil then it is not impossible that this man may attain salvation.