Thank you for your explanation tiki. I am curious, because it seems to me that Catholic theology says that our sin nature is wiped out at baptism. Is this correct? We lose original sin, this is the same as a sin nature? Thus we are a new Adam, with one nature, able to completely be unified in our hearts by following God. Calvinist theology, as I understand it, says that once we are called, we have two natures competing in our hearts. Before it was only our sin nature, we were incapable of following God because we didn’t know him, and after we are called it remains that our sin nature and our relationship with God compete. The Calvinist take makes sense to me, in that it explains the nature of man that I’ve observed, that we are not integrated, that we desire evil even as we do good (lust, desire, fantasy), and desire good even as we do evil (guilt, wishing we did the right thing, feeling bad even as we do wrong). The two natures explains this to me, sin nature and God. Washing completely clean through a sacrament doesn’t make as much sense since I have not seen the massive change in human nature that wiping out a sin nature would entail. I’ve always looked at the destruction of sin nature as being part of heaven.
We believe it frees us from Original Sin, we can still sin which is why we have Reconciliation which is also a Sacrament.
Baptism washes away original sin but does not take away concupiscence. Likewise, it remits the punishment of everlasting death, but we still will all die our natural death. Thus, just as Scipture says, a cleaned person could be subsequently overcome by 7 demons worse than the orginal one. So there is a real effect, a necessary one, but there are plenty of choices to be made afterwards with free will :) that can cause a person’s downfall.