'Fighting' in the Bible

My loved ones, while my thoughts were full of a letter which I was going to send you about our common salvation, it was necessary for me to send you one requesting you with all my heart to go on fighting strongly for the faith which has been given to the saints once and for ever.

Now when Michael, one of the chief angels, was fighting against the Evil One for the body of Moses, fearing to make use of violent words against him, he only said, May the Lord be your judge.