We might think that, (and is a nice happy thought, too) but doesn't comport with the Word of God.
By it's very meaning truth is exclusive - there can't be "many" truths, only one.
A person, having free-will either believes what the Word of God says or believes in a truth that he himself manufactures.
I am not God, I believe what He says about the nature of reality, and of life and death.
"Today is the day of salvation..."
Permit me to make a point here that reflects both Catholic sensibility and Protestant thinking. Even as it is important for us to try to practice Christianity in a truthful way, we should not make it into a hard test that permits only the best to pass.
Or, to put it another way, I believe that Jesus means for salvation through Him to be generously offered, broadly available, and rarely if ever refused. Faith in Christ matters most of all, with details and doctrine far less important though than having a Christian heart and spirit and practicing Christian virtues as best we can.
To get back to the example of the atheist professor who was scornful of Christianity, he was saved because after died and his soul was being dragged into Hell, he called on Jesus for help -- and he was saved. Jesus did not refuse the man for his faults and sins and lifetime of scornful disbelief. Jesus saved the man because, on the brink of damnation, he declared his faith and asked for help.
There are Catholics and Protestants who may be unsettled by the professor's account and reject it. After all, many seem to think that Judgment will include a detailed examination of the specifics of Christianity, a kind of grand final test, with Hell as the punishment for wrong answers.
No, I am confident that what Jesus said is true: “I am the resurrection and the life. Those who believe in me, even though they die, will live." And so the atheist professor was saved when he declared his faith in Jesus.