Romans 1:9-10

For God is my witness, whom I serve with my spirit in the gospel of His Son, that without ceasing, I mention you always in my prayers, making request if, by any means, now at last I might find a way in the will of God to come to you.
Romans 1:9-10, Modern English Version (MEV)
 
We find the following helpful information in Albert Barnes’ Notes on the Whole Bible:
 
Verse 9 (Romans 1:9)
 
For God is my witness - The reason of this strong appeal to God is, to show to the Romans the deep interest which he felt in their welfare This interest was manifested in his prayers, and in his earnest desires to see them. A deep interest shown in this way was well suited to prepare them to receive what he had to say to them.
 
Whom I serve - See Romans 1:1; compare Acts 17:23. The expression denotes that he was devoted to God in this manner; that he obeyed him; and had given himself to do his will in making known his gospel.
 
With my spirit - Greek, ἐν en, in my spirit, that is, with my “heart.” It is not an external service merely; it is internal, real, sincere. He was really and sincerely devoted to the service of God.
 
In the gospel of his Son - In making known the gospel, or as a minister of the gospel.
 
That without ceasing - ἀδιαλείπτως adialeiptōs. This word means constantly, always, without intermission. It was not only once, but repeatedly. It had been the burden of his prayers. The same thing he also mentions in regard to other churches, 1Th 1:3; 1 Thessalonians 2:13.
 
I make mention - I call you to remembrance, and present your case before God. This evinced his remarkable interest in a church which he had never seen, and it shows that Paul was a man of prayer; praying not for his friends and kindred only, but for those whom he had never seen. If with the same intensity of prayer all Christians, and Christian ministers, would remember the churches, what a different aspect would the Christian church soon assume!
 
Always - This word should be connected with the following verse, “Always making request,” etc.
 
Verse 10 (Romans 1:10)
 
Making request - It was his earnest desire to see them, and he presented the subject before God.
 
If by any means - This shows the earnest desire which he had to see them, and implies that be had designed it, and had been hindered; see Romans 1:13.
 
Now at length - He had purposed it a long time, but had been hindered. He doubtless cherished this purpose for years. The expressions in the Greek imply an earnest wish that this long-cherished purpose might be accomplished before long.
 
A prosperous journey - A safe, pleasant journey. It is right to regard all success in traveling as depending on God, and to pray for success and safety from danger. Yet all such prayers are not answered according to the letter of the petition. The prayer of Paul that be might see the Romans was granted, but in a remarkable way. He was persecuted by the Jews, and arraigned before King Agrippa. He appealed to the Roman emperor, and was taken there in chains as a prisoner. Yet the journey might in this way have a more deep effect on the Romans, than if he had gone in any other way. In so mysterious a manner does God often hear the prayers of his people; and though their prayers are answered, yet it is in his own time and way; see the last chapters of the Acts .
 
By the will of God - If God shall grant it; if God will by his mercy grant me the great favor of my coming to you. This is a proper model of a prayer; and is in accordance with the direction of the Bible; see James 4:14-15.