>>656209
>He knew He was immortal
nope, He knew he would give His life for the sacrifice of all sins. He knew he would be resurrected into His Glorified form, and then assume (or re-assume) His rightful place in Heaven.
there's many reasons aside from the sacrifice itself, but one of the big ones is proving:
1. He is God, and would rise again. He repeated this many times during His ministry.
2. The proof that He will raise us into glorified forms during the Final Judgement is Himself
and much, much more.
technically, all those whom are elect are already immortal! do you find issue with this too?