By whom we have received grace and apostleship, for obedience to the faith among all nations, for his name:  (6)  Among whom are ye also the called of Jesus Christ:  (7)  To all that be in Rome, beloved of God, called to be saints: Grace to you and peace from God our Father, and the Lord Jesus Christ.

Rom 1:5-7 

Explanation:

Christ was the source of grace for Paul by which He was saved.  He also said that it was by Christ and His grace that He had been called to be an apostle or sent one.  Christ was the source of His salvation, and also the source of his sending.

Why was he sent?  There were two reasons for his sending mentioned here.  First, that there would be people among all the nations of the earth that would become obedient to the faith.  They would believe the Gospel.  There is a body of doctrinal truth that God wants us to know, believe, and live out. When that process happens the second reason for his sending is realized- that God’s name would be made known and exalted among the nations.

Christ’s purposes in saving and sending Paul were being realized by the Romans obedience to the faith.  Paul is writing to them and saying from the beginning that there existence as people who believe and obey the Gospel is evidence of what God was doing in the world. He tells them that they are loved by God, called to be sanctified or set apart ones, and then greets them with a Gospel greeting.  

Application:

Because of salvation we have both grace from God and peace with God through Jesus.  God can give us what we don’t deserve (grace), and doesn’t have to give us what we do deserve (judgement) because of what Christ endured on the cross for us. Thus we have peace with God instead of condemnation.

Response:

Take a few moments  to think through what the Gospel means for the nations.  What should a believer in Christ do when it comes to evangelizing the nations?