Romans 1:2

the gospel he promised beforehand through his prophets in the Holy Scriptures

(v2, NIV)

Paul is set apart for the gospel of God. In these next few verses, Paul begins to talk about this gospel. The first thing he mentions is that it was promised beforehand. The gospel is not something that was recently thought up. The gospel is not some new way of thinking or thought that just so happened to surface. Instead, the gospel was planned a long time ago. We can see this through the prophecies of the Old Testament. Jesus was prophesied about long time ago and he came to fulfill those prophecies. Christianity is not a new religion. Christianity is the fulfillment of an old religion - Judaism. Also, since God's promises have been fulfilled and continue to be fulfilled, we know that God keeps his promises. God is faithful to what he says and we can trust in him.

God's promises regarding the gospel are through his prophets in the Holy Scriptures. God spoke through these men which are now written down in the bible. The bible is comprised of writings of men who were inspired by God. Basically, God wrote what was in the bible through a bunch of different people. The bible is quite precious; God wrote a book for us to read. In it we can find his promises and see them come to fulfillment. Now, you might think it's silly to read a book about a "god" who makes promises and fulfills them in the same book. You may think that's somewhat biased and unbelievable. It may be hard to believe, because it is only possible by the work of God. In addition, the bible isn't simply one book, but a number of different writings by a number of different people spanning hundreds of years. I'm not going to go into great detail, but the bible is quite amazing and it is from God. If you don't believe me, read it and research about it yourself.