If you come to faith (marry Christ), then lose your faith (cheat on your wife), then it is impossible to renew your faith to repentance, as Jesus can not be sacrificed on the cross a second time for you.
People can repent from all sin no matter how grave it is and still be saved, except the unforgivable sin of blaspheming the Holy Spirit. Christ's incarnation and sacrifice is cosmic in scope and not limited in time and space (i.e. each individual's sin but man's sinful nature as a whole). It was the undoing of the fall of Adam and bringing man back to eternal life (through salvation within the Church) by defeating death. He assumed human nature and lifted it up. God became man so that man can become god.
I agree with most of this.
People can repent from all sin no matter how grave it is and still be saved, except the unforgivable sin of blaspheming the Holy Spirit. Christ's incarnation and sacrifice is cosmic in scope and not limited in time and space (i.e. each individual's sin but man's sinful nature as a whole). It was the undoing of the fall of Adam and bringing man back to eternal life (through salvation within the Church) by defeating death. He assumed human nature and lifted it up. God became man so that man can become god.