No one takes a strong man's house. He wasn't telling you to let them abuse you to death nor your family. He said these things to give a chance at redemption and forgiveness.
Now think about this: If you love only those who love you, what credit is it to you? Love your enemies and bless those who curse you.
In order to stop the evil, you have to give them a chance to change their minds because if you only love those that love you, you will never vanquish evil. Someone has to try, then if they refuse you are justified.