"I will give you 10 million Dollars"
Would you believe this promise? Then why should I believe in a 2000 year old promise?
The promise of everlasting life also is one such.
Well, if you are God, then one could believe what God says.
I find it's more than a 2,000 year old promise because Revelation 22:2 traces right back to Eden.
That ' healing ' for earth's nations begins with the promise found at Genesis 3:15.
( that promised ' seed ' (Messiah) proved to be Jesus )
Although the promise was made in Genesis, Scripture teaches it would Not be near - Luke 19:11-15.
When Messiah would arrive he would at first be here a short while then go away for a long time before returning.
The passing of time was needed for us to have the opportunity to be born and to think who we would like as Sovereign over us.
I see No reason to not believe God's promise to father Abraham - Genesis 12:3; Genesis 22:18.