How does Paul attack those who question his authority? Paul's authority as an apostle was questioned by the Galatian church, so he emphasized at the beginning of his letter that his authority came from God. Moreover, in Galatians, Paul did not use the words of love such as "saints" or "dear", which shows that this is a severely worded letter. In his letter to the Philippian church, Paul claimed that he was a servant rather than an apostle, because the Philippian church lacked unity in the Lord. Perhaps he wanted to teach the Philippian church from the beginning, and the foundation of unity is to have a servant-like humble style and attitude first.