John 8:24, 28

That is why I told you that you will die [unforgiven and condemned] in your sins; for if you do not believe that I am the One [I claim to be], you will die in your sins.” [Ex 3:14; Matt 24:5; Mark 13:6; Luke 21:8]

So Jesus said, “When you lift up the Son of Man [on the cross], you will know then [without any doubt] that I am He, and that I do nothing on My own authority, but I say these things just as My Father taught Me.