2nd Corinthians 11:3 But I fear, lest by any means, as the serpent beguiled Eve through his subtlety, so your minds should be corrupted from the simplicity that is in Christ.
Persons with a good understanding of God and His word will not only view God’s law as being absolute and final, they would go a step further by avoiding anything God does not like, even if it might not be written in stone. If Christ shows His displeasure for something, that should be sufficient for believers to shun it too, instead of waiting for fine print to tell us so, in no uncertain terms.
That is what is meant by being led by The Spirit, for The Holy Ghost may lead us to avoid things that are not specifically written, but which, if harbored will prove detrimental to spiritual growth. That is why the Bible gives us a much wider perspective, and broader panoramic view, of what it means to obey God, other than following a strict “It is written” code of conduct.
When the system of sacrifices was first instituted, all the descendants of Adam were expected to bring a lamb as an offering to God thereby showing their faith in the promised, coming Redeemer. And even though the Bible does not specifically say in Genesis 4 that it was given in legal format, yet it was what God had ordained, and as such it was not to be viewed as being optional or a merely a good suggestion. It was law, and as such, any deviation from it would be sin.
James 4:17 Therefore to him that knows to do good, and does it not, to him it is sin.
May The Lord add His blessing to the study of His word. God bless!