Thoughts on Mortal and Venial Sins

This is a continuation of a discussion started here: http://cyberbrethren.typepad.com/cyberbrethren/2008/08/these-works-are-done-by-believers.html

I didn't want to continue my thoughts there because the discussion seemed to get a little heated, and thought my thoughts would be more productive here. Besides the fact that it was a little off topic from the original post.

The topic is the Lutheran view of mortal and venial sins.

What there seems to be consensus on is that, ultimately, what determines a mortal sin is whether faith remains after the sin is committed.

To an unchristian, all sins are mortal.

It was originally stated in the discussion that certain sins were not damaging to faith, namely the sin that unfortunately adhere to all our good works. The argument was that these were venial sins and thus not damaging to faith. First off, nowhere that I have seen has any Lutheran taught that certain sins, whether venial or not, are not damaging to faith. I feel confident when I say: All sins are damaging to faith. I can't see how rebellion against God and faith can go hand in hand.

I made the claim, based on the words of the Book of Concord, that the only sins a Christian can commit, and still remain a Christian, are venial. Being that the Book of Concord make the strong claim that mortal sin cannot coexist with faith.

Second it was stated: "If you say that open manifest sins like adultery and murder are venial sins when committed by Christians you are in error. By such sins holy Christians become unholy, that is, they cast out the Holy Spirit and faith."

I take big issue with this. As far as I have been able to tell, Lutherans have never been in the business of naming what are, and what are not mortal sins. Technically speaking, Catholics don't even go this far, only naming certain sins "grave and serious matters." To say that any Christian who commits adultery has no faith seems a little radical.

It seems to me, and it seems from what I have read, that mortal sins are not so much what the sin is as much as what the effect of the sin is. In this sense, which I think is highly supportable, any venial sin can become mortal. Certain sins may certainly be more damaging to faith, but to say a sin is mortal in itself is wrong. This can be supported from a number of sources. C.F.W. Walther writes: "All these texts prove that the so-called venial sins are not venial in themselves, in their nature, but damnable, mortal sins. (Law and Gospel, 329)" Likewise J.T. Mueller writes (I don't have the first volume of Pieper handy, though I would assume it would say the same thing): "On this point the papists err, who teach that certain sins are in themselves mortal, while others in themselves are venial. (Christian Dogmatics, 231)"

Therefore it is not what the sin is, but whether the sin results in the expulsion of the Holy Spirit and ones faith, that makes it a mortal sin or not. This can be a case to case basis. As Mueller writes: "when judging whether one sin is more grievous than another, we must consider a) the person sinning; b) the impelling cause; c) the object involved; d) the Law violated; e) the consequence of the sin. (231)"