The Lord God foretold of a coming Redeemer in Genesis 3:15 when He spoke of the seed of the woman who would crush the serpent's (Satan's) head
In fact He did NOT. He simply said that the seed of the woman (mankind), would bruise the snake's head, and the snake would bruise his heel. This happened continually from that day forward. There was no way in which Adam and Abel could possibly have known the later Messianic interpretation which would be put on the verse and indeed Paul applied it, not to Christ, but to all Christians (Rom 16.20). God was initially referring to the continual battle between men and snakes, and then, when the idea of Satan had developed, between men and Satan.
It was only once the concept of the Messiah arose that the verse was given a Messianic interpretation.
and He also apparently killed an animal by which He made coats of skin for both Adam and Eve.
There is no hint whatsoever in Genesis of any idea of atonement. Indeed you will note that there is no reference to the killing of an animal. 'God made for them clothing of skins'. The animal may have died naturally, or it may have sloughed its skin. It was only later when the concept of atonement through sacrifice grew that anyone would read back atonement into it.
Cain and Abel's parents must have passed such knowledge along unto their children or they must have had the same revealed unto them by God Himself or else the Lord wouldn't have chided Cain in relation to his sacrifice.
No such knowledge was known or passed on. They were not 21st century Americans. Cain was not rebuked for offering a meal offering. Meal offerings were always perfectly acceptable. He was rebuked because of his general behaviour. He had not 'done well'. Sin lay at his door.
Abel's sacrifice resulted in him having righteousness imputed unto him because he offered it in faith of Christ.
Christ is not mentioned in the Old Testament before Daniel. So how could Abel offer it in the Name Christ.? He offered his gifts to God. Nowhere does it say that righteousness was imputed to Abel 'because of his sacrifice'. It says that it imputed to him because of his faith revealed through his gifts.. You read far too much of your own opinions into what you read instead of taking it literally.
The Old Testament saints looked ahead to the cross whereas the New Testament saints look back to the cross.
Nonsense. The Old Testament saints knew nothing about the cross, nor about a suffering Servant before isaiah. It is
WE who talk about them looking forward to the cross.
It is dishonest to impute to Old Testament saints ideas which they did not have.
