Had a intresting interaction with my agnostic brother about orthodoxy and would like some help defending these points in the future

I(14m) was at teh bus stop with my brother(20m) and for whatever reason during our conversation he brought up that republicans are taking away womens rights i asked what rights(knowing the answer) and he said right to abortion he claimed that the baby isnt alive and therfore doesnt have the right to not be killed and said it would be worse for the baby to grow up in the dysfuncrtional family or even the mother would kill the baby due to stress i said that "they could put the baby up for adoption" but he said instincts would prevent that. he also then said that religion is a control tool and that the apostles had mas hysteria and most miracles are aswell and claimed the orthodox church is being used as a propoganda tool by russia? saying there are ways to hear brodcasts or smth idk. he also said evolution disproves the bible since we can "evolve ourselves into existence with protiens" idk what his source was i asked and he claimed that that was like asking "if oxygen is in air"

anyways the next part is that my moral argument was "you cant have objective moral foundation without religion" and he disagreed saying you dont need to and he can make his morals himself. he then claimed most historians who use the bible as a source would be mocked and laughed at and he said he knew historians and most of them are extreme atheist and would never say the bible is historically accurate or could be used as a source.

i then mentioned that without God there is no objective purpose to living and he said you can "make it yourself" and i said no you cant cause it wouldnt be a objective purpose it would be delusion if anything. he then ended it off by saying it seemed i was having a existential crisis and was looking for purpose idk how to feel now cause he did kind of fry me up in the debate i had no good responses. i should also mention i am not truly a member of the Orthodox church(though plan to be baptised as soon as i get my own place) and do not have a priest whom i can ask these quesitons to thats why i am saying this here