The following is from "Remember the Lord's Day" by Dr. Peter Masters. You can purchase the bookhere
IS IT IN THE CONSCIENCE?
Some modern teachers use another argument to remove the fourth commandment from its place in the ten. They say that if it were an ongoing moral commandment, it would be written in the heart or conscience of everyone, like the others, but it is not, and is therefore non-moral. This is a very shaky way of deciding whether a commandment has moral standing, elevating human endorsement above the Word of God. Since when was it a valid principle of interpretation to make our subjective feelings a judge over Scripture?
The reality is that moral commandments are frequently dulled and blotted out of the conscience by habitual disobedience, and especially by a culture of disobedience. Paul tells us in Romans 7 that he would not have known he was a sinner except by hearing the law, adding specifically: ‘I had not known lust, except the law had said, Thou shalt not covet.’ He speaks of how he lived seemingly undisturbed by his covetousness until ‘the commandment came, sin revived, and I died,’ meaning that the commandment revived his conscience and his awareness of the sin, and he felt condemned.
This reflects the experience of countless people who have never experienced a single pang of conscience while happily feathering their nests with this world’s goods. It never occurred to them that they were victims of the lust of greed, until they came under the sound of the Word.
The same is true of so many young people today, who are taught that sexual activity is an essential human right, and who are brainwashed by television soaps and films propounding the same ideas. Many young people are ‘sexually active’ from an early age, and we encounter those who feel no natural inhibitions or subsequent shame whatsoever in connection with such sexual activity, because their young consciences have been ‘seared with a hot iron’, and rendered insensitive (1 Timothy 4.2).
How much more will the conscience be desensitised to the obligation to allocate to God a regular portion of one’s life to worship, in an atheistic society where people have only ever known Sunday as a leisure day, and virtually everyone sees it that way!
The greatest tragedy of all in this matter, is that some Christian preachers are among those who are busy desensitising consciences by teaching that the fourth commandment is entirely ceremonial and of no moral or spiritual standing. It is surely awful that representatives of the Lord should set themselves against one of God’s abiding commandments, and encourage Christian people to spiritual compromise.
A well-known Puritan response to the claim that the fourth commandment is non-moral because it is not engraved in the conscience, points out that Adam, who doubtless possessed a well-primed moral consciousness, nevertheless had to be told about the law of the sabbath. In other words, it is an exceptional moral law in that it must be introduced into the conscience by announcement. It is certainly very agreeable to the consciences of Christians (except the worldly kind) who generally respond to it with a strong, natural inner sense of keen obligation.