Is protecting someone a sin?

A lot of Christians told me I should just let it happen or pray that God helps them.

I asked one time is it sin to defend my friends or my partner if they get attacked by maniacs or wanted them to be raped.

Some saif I should let that happen because its said I should turn other cheek and other said that rape is in God's way and I shouldn't try to defend it.

Is it sin to defend someone meaning you must hit them or telling someone to go away in loud voice if they are bothering you and bullying you.