Jehovah mentioned Jesus in the Genesis 3:15 prophecy.
That was at the beginning of human history.
The fact that we still have a record of it today shows people have been talking about it from that time to this.
As regards the word "opposers" - I do not subscribe to the fantasy world teachings that some psycho-students do ("psycho" short for "psychology" of course) that theories take precedence over reality.
There are people who oppose truth in the world. There are people who oppose God. Making up theories and fairy tales doesn't negate reality.
God exists. If a person wants to reject Him, He will reject that person. Opposing the source of life is a way to embrace death. How's that fit into your rejection model?