Re: God revealed that Israel would be his chosen

Yes, of course both testaments are inspired by God, and together make up our Bible. However, you have forgotten a basic rule of interpretation - The New interprets the Old, not the other way round. The NT writers uniformly interpet the OT promises, prophecies, etc, as finding their fulfilment in the New Covenant instituted by Jesus.

Your favourite site will almost certainly ignore this fact, coz it cannot be reconciled with its basic premise of a separate destiny for Israel after the flesh.