One of Paul’s purposes in visiting Rome was to receive help to get the gospel all the way to Spain.
The rejection of Jesus by many Israelites is God‘s plan for the salvation of the nations, and even of Israel itself.
In Stephen's speech before the Jewish Council, he gave a master class on the meaning of Old Testament history, which culminated in Jesus.
Although the nations are constantly in rebellion against the Lord, he has established his Son as King over the whole world.