My brother keeps trying to control me, maybe because I'm Muslim and he's not

As-salamu alaykum. My brother left Islam and now calls himself an atheist, and he really dislikes our faith. Lately, he's gotten kind of bossy with me. He keeps ordering me to study, which he never did before, and even tells our mom when I'm behind. He makes fun of me in front of her and tries to point out every little mistake I make. I feel like he wants to put himself above me because deep down he isn't confident in his atheism. He once said that even if Islamic miracles were true, they wouldn't prove anything-just that the Prophet Muhammad, peace be upon him, somehow knew the future but we don't know how. Honestly, that just sounds like he's grasping at straws. What I'm seeing is that since he's in the wrong and I'm on the truth about Islam, he tries to act bigger and make me seem small. He spends hours every day watching those atheist videos. It's clear he's struggling and Islam has left him with no solid arguments. May Allah keep us all steadfast in our deen.