Regarding the issue of whether Christians have an “absolute” assurance of salvation, regardless of their actions, consider this warning Paul gave: “See then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness; otherwise you too will be cut off” (Rom. 11:22; see also Heb. 10:26–29, 2 Pet. 2:20–21). The problem comes in that Catholics appear to think that it is possible to not sin and when they do to confess every sin they commit.
If you don't have assurance of your salvation that means that you have to do something to keep it, and that is not possible either. See post 37 where Paul addresses that.
It's faith beginning to end. Otherwise man would have something to boast about before God.
Is someone who believes/trust their salvation in Christ but commits adultery and leave their earthly partner in Christ for the affair partner, murder, perpetually lie, covet their neighbor's goods, fornicate every Saturday night but still go to Church Sunday morning, steal but know they can ask forgiveness so all is good o they can go ahead and keep the stuff, and constantly treat their neighbor like crap still saved?
Calvinism has spiritual/intellectual problems as well in light of all the Catholic bashing, Baptist bashing, Luther bashing, etc... constantly being bandied about. Christ did all the work, however the theology of the “Christian has no responsibility how they act” is extremely short-sighted. Jesus is Lord's verse on post #3 pointed out the futility of that theology.