Seth (שֵׁת - appointed or possibly chosen) was the fifth human, third son of Adam and Eve, and brother to Cain and the late Abel in the Book of Genesis. Seth took the place and role of his brother Abel, by continuing the worship of God through his ancestors. When he was 105 years old, his wife gave birth to Enos. He was the first of the "messianic" or Christological line, being a direct ancestor to Jesus Christ.
As with all those mentioned in this first genealogy, he and his wife would have many children.
Seth was born when his father was aged one-hundred and thirty. He is referred to as a son in his father's "own likeness", perhaps to distinguish him from various other sons that Adam had fathered over the course of a century. This distinction may be that Adam realized this son would be the one to continue worship of God, compared to Cain.
When Seth was born, Eve gave him his name because she saw God had granted her a child in place of Abel.
Creating a lineage
At the age of one-hundred and five, Seth's wife gave birth to his first son Enosh. After the birth of Enosh, people began to call on Yahweh once again as their God. This may have been due to the work of both Seth and Enosh working on creating a alternate society that of the Cainites.
Seth would outlive his father by 112 years, in which he would long hold the "title" of oldest man alive. Not only was Seth able to see his grandson, but was able to see all of the Sethites born, except for Noah- the last Sethite.
In his long life, he would witness a time of faithfulness to God during his son Enosh's life. He would be there when Enoch began his ministry during the troubling times near the end of the first millennium. He would most likely be among those who looked for the preacher when he disappeared.
In the eight-hundred and seven years he lived after the birth of Enosh, he would bare several other children
He would die in (aprox BC 1042) at the age of 912, just 14 years before the birth of Noah..
After Seth's life, he is only mentioned twice more throughout the Scripture, both in genealogies. He is mentioned in the genealogy in the First Book of Chronicles as an ancestor of Noah. He is also mentioned in Luke's genealogy in his gospel that traces Jesus genealogy backwards through his adoptive father, Joseph. Seth is listed as the third in the "lineage" of God, being the second human listed on the genealogy.
From these examples we can gather that Seth's greatest legacy was found through his lineage. Only through his lineage did Yahwism continue, was Noah found righteous, and one day was the Messiah born. Seth would see the birth of all of the Sethites, except the last one Noah. It was the family and ancestors of Noah that was considered righteous during the flood.
Most importantly, the Sethites provided an alternate to the Cainite influence over society. In the end the Cainite philosophy (any false religion or false idea of God) dominated the world, leaving Noah, a Sethite, as the only righteous man at the time of the Flood ,