Death, not sin, is the great problem for Israel’s patriarchs. 

There is remarkable little talk of “sin” in Genesis. Sin waits for Cain (4:7), the sin of Sodom rises up before the Lord (18:20), Abimelech sins against Abrhaham (20:6, 9), Joseph refuses to commit the sin of adultery with Potipher’s wife (39:9), Reuben warns his brothers not to sin against Benjamin (42:22), and the brothers confess their sin to Joseph (50:17). 

Sin is described in other terms: Noah is rescued from a world of violence, and the men of Babel defy God (but Yahweh is remarkably nonchalant as he confuses and scatters them).

Abraham doesn’t struggle against sin, but is confronted by death everywhere he goes. His wife is barren. His own body is growing old. The land that Yahweh promises him suffers from famine. When he finally is given the son he has waited for, Yahweh tells him to sacrifice him on Moriah, to put him to death.

The main noun for sin appears only 4x in Genesis, 9x in Exodus, then 66x in Leviticus, the most of any book of the Old Testament. Sin is not the big issue at the beginning. Sin becomes the big issue when the law is enacted, precisely the kind of thing Paul says in Romans 7: Law provokes sin of every kind.