I'd like to ask what people here would think that a world where Christianity doesn't exist look like? In my thought experiment (as I am a theist), I'm considering that Christianity is yet to be founded (Jesus Christ will come in 20 years).

A bunch of things are obvious. No crusades, no inquisition, no popes, no Jesuits, no Martin Luther (reformation), etc. But I'm saying what if everything that Christianity has contributed to civilization was also gone.

For example, the study of genetics started when Gregor Mendel was an Augustinian friar and while he was living that life. So we'd probably get the study of genetics much later. Galileo's heliocentric model had many Jesuit scholars help him with the calculations. Maybe Galileo couldn't have finished his model.

On another note, would monotheistic religions have been widespread? With the exception of Judaism and Zoroastrianism, other religions would've been polytheistic. Would Islam have been founded? Maybe.

Would there actually be less wars or would people still find things to fight about? How different do you think our world would be today if Christianity is yet to be founded in the future.

Note: needless to say, you can include both positive and negative effects of this.