Romans 15:20

20 So my aim is to evangelize where Christ has not been named, in order that I will not be building on someone else's foundation,

Romans 15:20 In-Context

18 For I would not dare say anything except what Christ has accomplished through me to make the Gentiles obedient by word and deed,
19 by the power of miraculous signs and wonders, and by the power of God's Spirit. As a result, I have fully proclaimed the good news about the Messiah from Jerusalem all the way around to Illyricum.
20 So my aim is to evangelize where Christ has not been named, in order that I will not be building on someone else's foundation,
21 but, as it is written: Those who had no report of Him will see, and those who have not heard will understand.
22 That is why I have been prevented many times from coming to you.
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