Why would god want billions of people to burn in hell?

Now, just thinking, only about 1 billion people are christian ton the planet, now it wouldn't make sense for god to banish everybody else to hell eternally for not believing in Jesus, some people have never even heard the name Jesus Christ, do they deserve to be burnt in hell forever for something they never knew about? And besides, burning in hell for eternity for a mistake is horrible! That's not justice, that's cruelty beyond imagination. Thank you for listening to my rant. Have a nice week.