Commit myself to the mission of the Lord

Acts 21:17-26
When we arrived at Jerusalem, the brothers and sisters received us warmly.
Then they said to Paul: "...all of them are zealous for the law. They have been informed that you teach all the Jews who live among the Gentiles to turn away from Moses,telling them not to circumcise their children or live according to our customs."
On his arrival Paul receives a warm welcome from his fellow-Christians, including the church leaders. But garbled tales are circulating, that Paul teaches Jews to abandon circumcision and the law. If he openly identified with a group of men under a strict vow all will see that he respects and observes the law. This issue looms so large that Luke makes no mention of the relief fund on which Paul set such store.
I do not place any value on my own life, provide that I complete the mission the Lord Jesus gave me - to bear witness to the good news of God's grace. (Ephesus 20:24)
Why?
Jews believed in Jesus Christ but they were zealous for the Law, they were limited under the law, abandoned the grace of the Lord!
Paul followed their suggestion for reduce the quarrel among Jews about his rumor.
Paul joined in their purification rites and payed their expenses. Paul do it for the mission from the Lord. 
How?
Do what I can to commit the mission of the Lord!