Paul says at 1 Tim 5.8: And whoever does not provide for relatives, and especially for family members, has denied the faith and is worse than an unbeliever.
To my mind this text reveals some critical insights about the relation of faith and works in the Christian religion. In an important way, the Christian faith is a more intensely moralist one than many contemporary commentators and believers realize. Here Paul straightforwardly affirms that a moral failing -- a relatively common one, one hardly given a second thought, in contemporary American culture! -- is apostasy. He does not say that it is as if such a person has denied the faith, but directly that such a person is apostate.
Such a person, moreover, is even worse than an unbeliever, presumably because he assumes the title of believer unworthily. It's one thing to be morally compromised and selfish, refusing to take care of your family when this is within your power, and you are just one more person in the world. In that case there is nothing particularly unique about you; you're one of the crowd. But Paul's condemnation presupposes that the Christian believer has an inherent duty to rise above the rest and to be a light.
Essential to Christian faith, then, is not just adopting certain moral standards and convictions -- "I am against this, and that, and this, and these things," etc. -- but also fulfilling them. To fail to do so in certain ways is heinous, effectively a failure to be a Christian. This is a critically important insight for the some of the recent discussions and controversies surrounding the issue of sanctification. It is strange to my mind that the doctrine of sanctification should even provoke controversy, especially when you consider the very rigorous moralism of the early Christians, say, for the first 1500 years or so. It is strange to my mind that preaching that Christians have moral obligations and that they ought to keep them, and that failure to keep them is serious and compromises their relationship with God, should be controversial.
Part of the problem -- he said as he began on a tangent -- is that in many circles, Christian salvation is defined in these exclusively extrinsic terms: your relationship to God was bad, but Christ died for your sins, and plus you are imputed his righteousness, so everything's good. None of this addresses you, your intrinsic being, your very existence, but only the relation in which you stand relative to other things. Since salvation was defined exclusively by reference to these external relations, it's hard to motivate sanctification. You may claim all you like that God gives the Holy Spirit to believers so that they are transformed, but this is a cause of sanctification and not a motive; or put another way, it is an efficient cause and not a final cause, and a doubtful one at that. How many people may actually believe but whose lives show little or no sanctifying transformation? The fact of Christian experience, it seems to me, is that it requires personal effort, a kind of synergistic participation with the Holy Spirit whom God gives. But this synergistic personal effort must be motivated -- and what is the motivation?
I think the solution is to introduce an intrinsic element of salvation through appeal to the vicarious humanity of Christ. Christ took upon himself a human nature such as mine, subject as it was to weaknesses and temptations, and sanctified and healed and redeemed it. My own human nature, too, can be transformed and healed by union with Christ through the means he has given me: baptism, the Eucharist, his teachings in the scriptures, the fellowship of other believers, the Holy Spirit who works in my heart, etc. The point here is that you are sick, your sin is a sickness which corrupted your entire being, and Christ has given you means by which to make yourself better through the help of the entire Holy Trinity. It's not about earning God's favor or grace -- he's already given you his favor and grace through the very diagnosis of your sickness (of which you would not have otherwise been aware) and the freely offered means of treating it. It's about no longer living in the sickness and death of sin.