How do we know that Paul was appointed by God as a minister?

In Acts 9, God explicitly designates Saul (Paul) as a chosen vessel to proclaim His name to the Gentiles and kings. This appointment underscores that Paul's ministry was not a result of human ambition but a divine calling determined by God. As stated in Ephesians 3:8-9, Paul sees himself as the least of all saints, a position filled not by merit but by the grace given to him by God. Thus, his role as a minister is firmly rooted in the sovereignty of God who equips and sends His ministers to fulfill the Great Commission.