The wages of sin is death Rom 6:23 and that has never changed. Sin is the transgression of God's law, His version 1 John 3:4 James 2:10-12 and we see these as the two choices blessed or cursed Rev 22:14-15That was the terms of the law at Sinai. Do you need references to them?
Because of sin God gave His only Son and if we have a right relationship with Him, He will give us eternal life. The bible is filled with how to have a right relationship with Christ, why the bible is a big book. Jesus came not just to take the penalty of sin, when we repent and confess, which means a change in direction, He came to show us the right way to live. He lived to be our example to follow, to follow in His footsteps 1 Peter 2:21-22 1 John 2:6 and if we abide in Him we will keep His commandments, just as He did, John 15:10 because He showed us the way. We can get off that path and make our own and follow someone else, but Jesus said: I am the way and the truth and the life. No one comes to the Father except through me.