Romans 1:8-13

8 First, I thank my God through Jesus Christ for all of you, that your faith is proclaimed throughout the whole world.  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,  10 requesting, if by any means now at last I may be prospered by the will of God to come to you.  11 For I long to see you, that I may impart to you some spiritual gift, to the end that you may be established;  12 that is, that I with you may be encouraged in you, each of us by the other's faith, both yours and mine.

13 Now I don't desire to have you unaware, brothers, that I often planned to come to you, and was hindered so far, that I might have some fruit among you also, even as among the rest of the Gentiles. 

Romans 15:20-24,30

20 yes, making it my aim to preach the gospel, not where Christ was already named, that I might not build on another's foundation.  21 But, as it is written,  "They will see, to whom no news of him came.  They who haven't heard will understand."

22 Therefore also I was hindered these many times from coming to you,  23 but now, no longer having any place in these regions, and having these many years a longing to come to you,  24 whenever I journey to Spain, I will come to you. For I hope to see you on my journey, and to be helped on my way there by you, if first I may enjoy your company for a while. 

30 Now I beg you, brothers, by our Lord Jesus Christ, and by the love of the Spirit, that you strive together with me in your prayers to God for me,