When a person sins against his conscience, that is, when he knowingly and intentionally acts contrary to God, as, for instance, an adulterer or any other criminal, who knowingly does wrong, he is, while consciously persisting in his intention, without repentance and faith and does not please God. For example, while a person keeps the wife of another man, it is manifest that he is void of repentance, faith, and holiness.
I think sometimes as Lutherans we point towards the grace of God to the point of our detriment. While it is faith alone that saves and not works, at times we put so much emphasis on it that sin is given a pass. We have our sins that perhaps out of habit we repeat over and over with maybe a prayer for forgiveness after the fact. I am not speaking of sins which we struggle with daily for we all have sinful natures that cause us to act out in a way that is unholy without intention and we feel greatly sorry after the fact. No, what I am referring to are those sins that we willfully do with the full foreknowledge that it is a sin before the fact that we commit it. I think it’s fair to say that many Christians, myself included, have at times committed the grievous error with the thought that we can just repent afterwards.
If I have the intention of getting drunk, rather than getting drunk by simple negligence, and then in the following weekend I intend to get drunk again, then it stands to argue that I am not actually repentant and my prayers for forgiveness are simple talk. Do you see the difference? In one situation I am drunk by intention and in the other I am drunk by my own stupidity. Both are sinful and abominable actions, but only one probably will carry with it true remorse and repentance. The other will simply go through the “Christian” motions to appease himself and those around him rather than have true contrition.
This holds true for any sin(s). It does not matter if it is theft, lust, drunkenness, violence, or anything else. If anyone is intentionally partaking in anything that is contrary to the word of God and willingly continues doing so, then it is suspect that any claims of repentance and faith are merely just talk and show. To struggle with sin (drunkenness, homosexuality, etc.) is one thing, but to continually indulge in that sin is no struggle. It is a willful and intentional middle finger to God.