'Messenger' in the Bible

Paul, called as an apostle (special messenger, personally chosen representative) of Jesus Christ by the will of God, and our brother Sosthenes,

Am I not free [unrestrained and exempt from any obligation]? Am I not an apostle? Have I not seen Jesus our [risen] Lord [in person]? Are you not [the result and proof of] my work in the Lord?

If I am not [considered] an apostle to others, at least I am one to you; for you are the seal and the certificate and the living evidence of my apostleship in the Lord [confirming and authenticating it].