Romans 1:9

‘For God is my witness, whom I serve in my spirit in the gospel of his Son, how unceasingly I make mention of you, always in my prayers,'

The use of this minor oath, calling on God as his witness, confirms how desirous Paul was to win the hearts of the Roman church. He was aware that many voices came to Rome and he was concerned that his voice should be heard above them. So he stresses before God that he ‘serves God in his spirit in the Gospel of His Son'. There is an echo here of the words of the introduction. Just as Jesus Christ was revealed as acting ‘according to the spirit of holiness' (Romans 1:4), so Paul acts ‘in his spirit' which is a spirit of servitude to God. He is the servant of the Holy One. And He is so in ‘the Gospel of His Son', that is in the Gospel of God, the Good News whose source is God, which is concerning His Son (Romans 1:1; Romans 1:3).

And it is because of his spirit's servitude to God that he unceasingly makes mention of them always in his prayers in order that he might at some stage be able to come and see them. He acts under divine compulsion as God's hired servant. Note how his prayers are ‘unceasing' (they occur day by day) and ‘always' (he never misses a day). Assuming it to be true, and the oath confirms it, we have an indication here of the depth of Paul' prayer life even in the midst of a busy schedule which included arranging the details of the Collection for the saints in Judea and planning the journey to Jerusalem.