Even the word "devil" can be translated as "to divide."
The devil loves chaos. Ever since his fall from Heaven Satan seeks to divide the world. His first action was to divide the angels, which was followed-up by tempting Adam and Eve in the garden, driving a wedge between the first humans and God.
Division is the devil’s playground and it shouldn’t be surprising. The word “devil,” comes from the Greek word diabolos, which can be translated as, “to divide,” “to separate,” or more literally, “to throw against.”
Pope Francis has spoken much about this tactic of the devil, speaking directly about it in an address to participants in a seminar for bishops in mission territories.
Divisions are a handy weapon that the devil uses to destroy the Church from within. He has two weapons, but the main one is division … Please, fight against division, because it is one of the weapons that the devil uses to destroy the local Church and the universal Church. In particular the differences, owing to the various ethnic groups present in the same territory, must not penetrate the Christian communities to the point of prevailing over their good. There are challenges that are difficult to resolve, but with the grace of God, prayer and penance, it can be done. The Church is called to rise above tribal-cultural connotations, and the Bishop, a visible principle of unity, has the task of unceasingly building up the particular Church in the communion of all her members.
Whenever we see division occur in the world, especially division that pits one group in society against another, we can affirm that the devil is in some way behind it. He wants us to destroy ourselves and hatred against other people is one of the fastest ways we become the authors of our own demise.
Jesus, on the other hand, desires unity.
I pray not only for them, but also for those who will believe in me through their word, so that they may all be one, as you, Father, are in me and I in you, that they also may be in us, that the world may believe that you sent me. And I have given them the glory you gave me, so that they may be one, as we are one. (John 17:20-22)
The Holy Trinity is the prime example of unity and communion, something we will ultimately participate in if we reach Heaven someday. Heaven will essentially be “communion,” where we are unified not only with God, but with each other.
Above all, we need to strive for unity in truth, coming together to fight against injustices with charity. If we can stay united together under the leadership of Jesus Christ, we are able to thwart the plans of the devil.