A student, Daniel Foucachon, gave some very thoughtful perspectives on Jesus’ instructions in the Sermon on the Mount. He noted that Jesus is not commending non-resistance, but a particular kind of resistance. Our resistance is modeled on Jesus’ own; He conquered by going willingly to the cross, and He instructs us to do the same in the details of life.
Regarding the instructions to give more than adversaries ask, he points out that the Bible says the borrower is the slave of the lender. When we give more than is demanded of us, we become lenders and place our opponent in the place of a borrower. Giving more than asked thus reverses the power relationship, so that the “oppressed” takes mastery of the situation. We really do “overcome” evil with good.
-Dr. Leithart, Leithart.com