Your blood be on your own heads! I am innocent of it. From now on I will go to the Gentiles

 Acts 18:1-17

In Corinth: Every Sabbath he reasoned in the synagogue, trying to persuade Jews and Greeks.

When Silas and Timothy came from Macedonia, Paul devoted himself exclusively to preaching, testifying to the Jews that Jesus was the Messiah. But when they opposed Paul and became abusive, he shook out his clothes in protest and said to them, “Your blood be on your own heads! I am innocent of it. From now on I will go to the Gentiles.

Then Paul left the synagogue and went next door to the house of Titius Justus, a worshiper of God. Crispus, the synagogue leader, and his entire household believed in the Lord; and many of the Corinthians who heard Paul believed and were baptized.

One night the Lord spoke to Paul in a vision: “Do not be afraid; keep on speaking, do not be silent. For I am with you, and no one is going to attack and harm you, because I have many people in this city.” So Paul stayed in Corinth for a year and a half, teaching them the word of God.

Just as Paul was about to speak, Gallio said to them, “If you Jews were making a complaint about some misdemeanor or serious crime, it would be reasonable for me to listen to you. But since it involves questions about words and names and your own law—settle the matter yourselves. I will not be a judge of such things.” 

Why?

Paul made an effort to preach Jesus as the Messiah to Jews. But most Jews refused to believe, even against Paul. They opposed Paul and became abusive, he shook out his clothes in protest and said to them. "Your blood be on your own heads!" How sad these Jews are, they have been the blood burden for many years until now.

The Lord is the master of Paul, under God's protection, Paul can keep on speaking and don't be afraid.

Paul has no crime so the officer did not like to judge the quarrel among Jews. 

For the word of the Lord came upon Paul, so Paul stayed in Corinth for a year and a half, teaching them the word of God. This is a real missionary.

How?

Go step by step on the way of the Lord arranged for me. Don't worry and be humble myself, what I can do is the grace of the Lord on me. Follow the guidance of the Holy Spirit to serve the Lord.