An Anti-Evangelion story would tell you nothing matters in life and you're better off accepting an abrupt end than believing you can continue and find happiness in your suffering but people's idea of something being Anti-Evangelion is it having bright colors and being "hopecore"
As someone who grew up christian, the religious imagery in Evangelion feels like it's there more so to evoke the feelings and existential dread associated with religious concepts such as God, eternity, sin, etc, rather than being actual symbolism for christian themes.
It's about the frustrations of human existence and connection in general. Suffering is inherent to life, people are lonely, we yearn for connection, and yet we are scared of it. That's what Evangelion is about.