When did Abraham appear on the biblical timeline from Adam to Christ?
Abraham appeared around 2000 BC, halfway between Adam's creation (about 4000 BC) and Christ's first advent. In the round timeline from Adam to Christ, Adam is placed at 4004/4000 BC, Christ at the first advent, and Abraham stands at the midpoint, roughly 2,000 years after Adam and 2,000 years before Christ.
Les reviews the timeline from Adam to Christ and places Adam's creation at about 4004 BC. He divides the timeline in round terms from 4000 BC to the time of Christ, noting this is not in exact years. The midpoint is the appearance of the man Abram, called Abraham, at 2000 BC—halfway between the creation of Adam and Christ's first advent. He adds that backing away from Abraham about 400 years in round figures brings us back to the time of the flood.