You didn't read far enough . . .
and perhaps you never read the earlier chapters of John?
"For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God" (John 3:16-18).
How does that smoke in your universal salvation pipe?
I have read the Book of John more than other Book in the Bible. It is my favorite Book.
Yes I have read the verse you reference countless times. Only I understand it for what it says.
Yes you must believe. I never said a non believer isn't saved. Where we differ in interpretations is you ignore the simply stated and twist other simple English to justify your theology. You also put a time limit on when one has to become a believer before they are saved. Before they actually die in the first life. You fail to recognize that it is not over when you die. Why would there be a tribulation? You do know the tribulation is resurrected people, do you not?
Also, to think the word condemned means "will be cast into the lake of fire" is utter nonsence and you have to just be not thinking about what it says. Think about this:
If they are condemned already, that means no one that was ever a non believer can become a believer. They are condemned to the lake of fire already. Condemned means they will suffer the penalty of sin. Death. Condemned to die. Everyone but 2 die in their sin. Enoch and Elijah.
If you keep my commands you will never taste death
The penalty of sin is death.
Also if you continue reading through there is more on the definition of the condemnation spoken about in your referenced verses.
19 And this is the condemnation, that light is come into the world, and men loved darkness rather than light, because their deeds were evil.
That is talking about all men. All but two not counting Jesus.
The salvation comes at the last day after the tribulation when that which the man had that caused him not to believe, is cast into the lake of fire. The devil and his angels. The ruler of this world.
The ruler of this world will be judged.
You can believe how like. Im good with it. If you are a human being, you will be saved eventually. You will believe eventually. Every knee shall bow.