He who believes in the Son has eternal life; but he who does not obey the son will not see life, but the wrath of God abides on him.John3-13

Yes, I quoted this from my American Standard Bible.

No one has ascended into heaven except the one who descended from heaven, the Son of Man (John 3:13, NRSV)

Enoch did. But I dont think thats what John 3-13 meant. It just meant that if you don't believe in Jesus our redeemer, repent and obey his commandments, you will die in your sin, and face final judgement from God, at the end of the age and return of our Lord Jesus. God MUST deal with sin because he is a good and just God that is without sin. That's why he came to earth and became flesh, to show us that we too can live a sinless life,  even faced with daily temptation and self will. He even died and paid the cost of our sin, and even provided a helper, his Holy Spirit, to write the Law on our hearts, and renew our sinful minds. The only condition is for us to repent and turn away from   sins. It doesn't mean we wont fall time and again, but unlike in the old testament, where the Holy Spirit was poured ON people to prophecy for God,  the Holy Spirit through Jesus, God in the Flesh, through his atoning death, pour his Holy Spirit INSIDE us to give us the ability to do Gods will and not our own. Its the only way to enter the kingdom of God in Heaven, and live our eternity with our Heavenly Father . He made it pretty simple because he provided us a helper to make us want to do his will. Without him, we can do nothing. But with him, everything is possible.