Exodus 31:13 Verily my sabbaths ye shall keep: for it is a sign between me and you throughout your generations; that ye may know that I am the Lord that doth sanctify you.
[Patriarchs & Prophets pp 80>81] The Sabbath was honored by all the children of Adam that remained loyal to God. But Cain and his descendants did not respect the day upon which God had rested. They chose their own time for labor and for rest, regardless of Jehovah's express command. Upon receiving the curse of God, Cain had withdrawn from his father's household. He had first chosen his occupation as a tiller of the soil, and he now founded a city, calling it after the name of his eldest son. He had gone out from the presence of the Lord, cast away the promise of the restored Eden, to seek his possessions and enjoyment in the earth under the curse of sin, thus standing at the head of that great class of men who worship the god of this world.
In that which pertains to mere earthly and material progress, his descendants became distinguished. But they were regardless of God, and in opposition to His purposes for man. To the crime of murder, in which Cain had led the way, Lamech, the fifth in descent, added polygamy, and, boastfully defiant, he acknowledged God, only to draw from the avenging of Cain an assurance of his own safety. Abel had led a pastoral life, dwelling in tents or booths, and the descendants of Seth followed the same course, counting themselves “strangers and pilgrims on the earth,” seeking “a better country, that is, an heavenly.” Hebrews 11:13, 16.
For some time the two classes remained separate. The race of Cain, spreading from the place of their first settlement, dispersed over the plains and valleys where the children of Seth had dwelt; and the latter, in order to escape from their contaminating influence, withdrew to the mountains, and there made their home. So long as this separation continued, they maintained the worship of God in its purity. But in the lapse of time they ventured, little by little, to mingle with the inhabitants of the valleys. This association was productive of the worst results.
2nd Corinthians 6:14 Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?
May God add His blessing to the study of His word. “Good night” and God bless!