For God is my witness, whom I serve with my spirit in the gospel of his Son, that without ceasing I make mention of you always in my prayers;
All Commentaries on Romans 1:9 Go To Romans 1
Gennadius of Constantinople
AD 471
When Paul mentioned “his spirit,” he was not speaking about the person of the Spirit but about the grace of the Spirit which had been given to him to preach the gospel and by which, once he had been made worthy to be a coworker with God, he was enabled to carry out his work of mission. .