Jesus speaks of bringing a sword instead of peace, which is seemingly shocking. And yet, when one considers that not all will believe in Jesus, it makes sense. When Jesus renews the hearts of some and others reject him, there will be conflict and division and a sword will split people apart. This is also true of ourselves. When Jesus renews our hearts, he creates a divide within us and puts us at war with ourselves. This is his work of redemption in us, to cut off the old that the new would rise up.
Image: Scenes from Matthew 10: 34-38, by Daniel Hopfer, Licensed under CC0 1.0. Image location: https://commons.wikimedia.org/wiki/File:Scenes_from_Matthew_10-_34-38_MET_DP835392.jpg