Apostle Paul wrote to the Galatians in defense of his ministry.
Through their faith and salvation in Jesus Christ, everyone became equal. As believers in Christ, they received freedom in the Spirit to serve one another in love, joy, peace, patience, kindness, faithfulness and self-control.
Once people accept Jesus Christ and have the Holy Spirit, they realize everyone is equal under God.
Then why so many violent Christians? Using the Christian label does not make people Christians unless they live in step with the Spirit by showing their fruits of love, joy, peace, patience, kindness, faithfulness and self-control.