Right from the start, Paul introduced the person of Jesus in the letter to the Romans. But Paul not only talked about Jesus himself but also about his impact and significance. For instance, Paul talked about how he and the Roman Christians "received grace and apostleship for obedience to the faith" (1:5). Paul and the Roman Christians obeyed the faith by believing in Jesus (since there were many calls from Jesus himself). Also, according to Merriam-Webster, "apostle" is "one sent on a mission", which is fitting for the role of Paul (and technically, the Roman Christians too).
Paul and the Roman Christians were also considered "the called of Jesus Christ" (1:6). In particular, they were "called to be saints" (1:7). From the Interlinear, the Greek word for "saint" (Strong 40) conveys a sense of holiness, which is basically being set apart by God.
And finally, Paul wrote to the Roman Christians, "Grace to you and peace from God our Father and the Lord Jesus Christ" (1:7). Grace and peace from Jesus are very significant (as we'll see later). In fact, these two can be considered the foundations of much of Christianity.