Elon Musk calls AI a 'fundamental risk to the existence of human civilization'. Basically, he's worried about Skynet. Skynet is a intelligent computer network that caused the end of civilization in the Terminator film franchise.

Psalm 139
For the director of music. Of David. A psalm.
1 You have searched me, Lord,
and you know me.
2 You know when I sit and when I rise;
you perceive my thoughts from afar.
3 You discern my going out and my lying down;
you are familiar with all my ways.
4 Before a word is on my tongue
you, Lord, know it completely.
5 You hem me in behind and before,
and you lay your hand upon me.
6 Such knowledge is too wonderful for me,
too lofty for me to attain. Psalm 139