We are often led to believe sin is merely an outward manifestation of an inward desire. Sin consists in the acting out of an inward disposition, a desire or perhaps an orientation. A desire or an orientation cannot be sin, it is commonly thought. However, we ought to meditate on the sweet Word of God before we take for granted any musing of man. There are many places, from the Scriptures, where it can be proven that inward desire or affections can indeed constitute sin. However, in this post, I will only focus on one passage.
The Apostle John writes:
Now when He was in Jerusalem at the Passover, during the feast, many believed in His name, observing His signs which He was doing. But Jesus, on His part, was not entrusting Himself to them, for He knew all men, and because He did not need anyone to testify concerning man, for He Himself knew what was in man (Jn. 2:23-25).
We will benefit in making two notes from this passage. First, the “many” who “believed” in Jesus had a false, or superficial faith. Second, it was the disposition of the hearts of these men leading Jesus not to entrust Himself to them. Either issue is ultimately an issue of the heart, and both are indicative of inward sin.
First, the faith these men professed couldn’t have been the true faith. For those with faith are referred to as the brethren of Christ (Rom. 8:29, 30). If these men were Christ’s brothers, why couldn’t He entrust Himself to them? Inwardly, they were self-idolaters, desiring the benefits of Christ without desiring Christ Himself. Their inward sin affected their false, exclusively external professions of belief.
Second, Jesus wouldn’t entrust Himself to these men, not because of anything they were doing at the time, but because He knew their hearts. Something in the hearts of these men was repugnant to Christ (1 Jn. 1:5). There is simply no name for a desire or disposition that offends a holy and righteous God other than sin. Let’s take this as a lesson from the Scriptures that sin indeed originates, rests, and festers in the deepest recesses of men, notwithstanding whether or not it is acted out.
Not all sin is acted out, yet every acted out sin is based on a pre-existing inward sinfulness.