If he preached the gospel of Christ from Jerusalem to Illyricum, it is obvious he was preaching the same gospel as Peter and the other apostles.1Cor 3:10 (AKJV/PCE)
(3:10) According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon.
Rom 15:19-20 (AKJV/PCE)
(15:19) Through mighty signs and wonders, by the power of the Spirit of God; so that from Jerusalem, and round about unto Illyricum, I have fully preached the gospel of Christ. (15:20) Yea, so have I strived to preach the gospel, not where Christ was named, lest I should build upon another man's foundation:
Put 2 and 2 together.
And, the same gospel Jesus preached in John 3:16-18..."For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.
17 For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
18 He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God."
Sounds like "good news" to me.