"What God has joined together,"....

Satan tries to tear apart!

The complete verse reads:
 "Therefore what God has joined together, let man not separate."  Matt. 19:6

In this verse Jesus is addressing the question of the Pharisees about divorce (Matt 19:3).

However, marriage is not the only area where Satan tries to separate people.
"Divide and conquer" is his motto and main goal, and he uses our disobedience to get there.

Disobedience creates separation between God and men, and among men.

Adam and Eve were send away from the garden because of their disobedience, separated from God and from their first home.

Cain's disobedience led to the murder of his brother Abel. As a consequence God separated him from his family.

And so it has been ever since: our disobedience separates us from God and each other.

But God had not intended it that way. "From the beginning it was not so." (Matt 19:8)
The Son's obedience is able to undo the separations Satan is causing.

"I and the Father are one." (John 10:30)
When Jesus lives in us, we are one with Him, and like Him, one with the Father.

Jesus said: "He who has My commandments and keeps them, it is he who loves Me. And he who loves Me will be loved by My Father, and I will love him and manifest Myself to him." (John 14:21)

One day we will be joined together with God forever.