Aristides, a second-century apologist for the Christian faith, wrote this to the Roman emperor Hadrian about believers in his day:
"They love one another. They never fail to help widows; they save orphans from those who would hurt them. If they have something, they give freely to the man who has nothing; if they see a stranger, they take him home, and are happy, as though he were a real brother. They don’t consider themselves brothers in the usual sense, but brothers instead through the Spirit, in God."
As human beings, we all belong to the same family. Even though we are divided by all sorts of barriers and differences, "under the skin" we’re all the same (Acts 17:26).
As believers in Jesus Christ, then, whatever our differences  denominations, preferences, worship styles  we are one spiritual body that acknowledges the same heavenly Father (Eph. 4:4-6). The example of our spiritual forebears can be an instructive challenge to us as disciples of Jesus in the 21st century.
Let’s do all we can to demonstrate our unity in Christ. Unity in our diversity is the most effective witness to this sin-fractured world. Vernon Grounds
Join hands, then, brothers of the faith,
Whatever your race may be;
Who serves my Father as a son
Is surely kin to me.  Oxenham
READ: Ephesians 4:1-6
Unity among Christians comes from their union with Christ.
The Bible in one year:
• Joshua 1-3
• Mark 16