For i long to see you, that i may impart unto you some spiritual gift, to the end ye may be established;That is, that i may be comforted together with you by the mutual faith both of you and me. Romans1:11-12.
Oh how Paul longed to teach, yet understanding that the same faith which is in him is in all of us [that is the gift of God], but yet he humbly and diligently preached the same salvation that saved his soul.
Not only that, but he wanted to impart the Power or Spirit of God that was imparted in him and therein is the comfort , knowing that we received It.