Thirdly, and here's the crux, be unbelieving...be unbelieving. In verse 24, "I said therefore to you that you shall die in your sins for unless you believe that I am He, you shall die in your sins." If you don't put your faith in who I am, which embodies all of My person and work, you will die in your sin.
That's the crux. Now the way of escape is open, the way of salvation is open. Believe in the Lord Jesus Christ and you will be saved, said Paul to the Philippian jailer. If you believe in your heart God has raised Him from the dead and confess with your mouth He is Lord, you will be saved. It's available. Salvation is offered.
But the one who persists in unbelief, who will not believe that Jesus is God, who will not believe that He is God in human flesh come as a redeemer to pay the price of sin, that He rose from the dead for our justification, that He is sovereign Lord...the one who will not believe that, who will not embrace in faith all that He is and all that He has done will die in his sins. And when He says, "If you will not believe that I am He," He is summing up the fullness of all that He is. God's name, you remember, "I am that I am." And to believe that Jesus is the great "I am" is to believe that He is all that He claimed to be. "I am," He said, "the bread of life. I am the living water. I am the light of the world. I am the good shepherd. I am the vine. I am the resurrection and the life." And if you believe that He is all that He claimed to be, and you place your faith in Him, you will escape death in its eternal consequence. But if you don't believe, you'll die in your sin.
In John chapter 3, you remember the last verse, verse 36, "He who believes in the Son has eternal life, but he who doesn't obey the Son shall not see life but the wrath of God abides on him." Just don't believe and you'll be damned forever.
To die in your sins, all you have to do is be self‑righteous, don't think sin is a big problem and believe you're already good enough, be worldly, get yourself totally engulfed in this system, be driven by the lust of the flesh, the lust of the eyes, the pride of life, serve your father, Satan, and then just refuse to believe that Christ is all that He said He was in a full expression of faith that embraces Him fully as one's own redeemer, just don't do that and you'll die in your sin.