Jesus asked His Father for what on the eve of His Crucifixion?

"...that they may be one, as You Father and I are one."

Elsewhere in Scripture we are told: "A kingdom divided against itself will be destroyed."

the "sword" and unpeace that Jesus referred to is the interior struggle that must go in inside of each of us to become ever holier, closer to God and His will for us.

The saying Yes to God when we want to do our own thing, make our own commandments.  That's where the battle goes on, daily.

And the Sacraments give us the energy to be cheerful children strugglers with Our Lord at our side, in each step we take.