Will Christians ever completely obey God in this life? Absolutely not. So then we shouldn’t work hard to grow in holiness or exhort others to do the same? Again, the answer is no. The admission of imperfection does not have to be the enemy of endeavor. We can keep trying even if we know we will never fully succeed.
Here’s how John Calvin puts it:
I do not insist that the moral life of a Christian man breathe nothing but the very gospel, yet this ought to be desired, and we must strive toward it. But I do not so strictly demand evangelical perfection that I would not acknowledge as a Christian one who has not yet attained it. For thus all would be excluded from the church, since no one is found who is not far removed from it, while many have advanced a little toward it whom it would nevertheless be unjust to cast away.
Makes sense. We are not going to be perfect. In fact, we are all light years away from the holiness of God. But Calvin’s not finished.
What then? Let that target be set before our eyes at which we are earnestly to aim. Let that goal be appointed toward which we should strive and struggle. For it is not lawful for you to divide things with God in such a manner that you undertake part of those things which are enjoined upon you by his Word but omit part, according to your own judgment. For in the first place, he everywhere commends integrity as the chief part of worshiping him [Gen. 17:1; Ps. 41:12; etc.]. By this word he means a sincere simplicity of mind, free from guile and feigning, the opposite of a double heart. It is as if it were said that the beginning of right living is spiritual, where the inner feeling of the mind is unfeignedly dedicated to God for the cultivation of holiness and righteousness.
So what’s the bottom line?
Let each one of us, then, proceed according to the measure of his puny capacity and set out upon the journey we have begun. No one shall set out so inauspiciously as not daily to make some headway, though it be slight. Therefore, let us not cease so to act that we may make some unceasing progress in the way of the Lord. And let us not despair at the slightness of our success; for even though attainment may not correspond to desire, when today outstrips yesterday the effort is not lost. Only let us look toward our mark with sincere simplicity and aspire to our goal; not fondly flattering ourselves, nor excusing our own evil deeds, but with continuous effort striving toward this end: that we may surpass ourselves in goodness until we attain to goodness itself. It is this, indeed, which through the whole course of life we seek and follow. But we shall attain it only when we have cast off the weakness of the body, and are received into full fellowship with him. (Institutes III.vii.5)
As is often the case, our forefathers knew a thing or two about good doctrine and sound practice. Calvin strikes the right balance between realism and effort, between trusting and trying, between accepting imperfection without excusing iniquity. We would do well to listen to the likes of Calvin as we seek to understand and apply a wise, Reformed, and biblical approach to sanctification.