Paul, who was previously a Pharisee, counts his accomplishments, his zeal, and his holiness as "rubbish" compared to the surpassing greatness of knowing Jesus Christ our Lord.
https://youtu.be/6VoR-g2wMNA We’re all familiar with the Golden Rule: treat others as you would like to be treated. Jesus mentions this maxim several times throughout the Gospels (e.g., Matthew 7:12; Luke 6:31), and when asked what the greatest commandment in the Law was, He answered that the entire Law and Prophets (the Old Testament) hung on the commands to love God…
We are defined by the work of Jesus, not our own. Knowing this gives us a proper perspective as it relates to loving ourselves, which in turn affects how we love others.