But when they resisted and blasphemed, he shook out his garments and said to them, "Your blood be on your own heads! I am clean. From now on I will go to the Gentiles." Acts 18:6
Christianity is an evangelistic religion. We are commanded by our Lord to “make disciples” (Matthew 28:18-20), which begins by evangelizing non-believers with the hope of seeing the Holy Spirit transform them into believers.
We do this by persuasion, not coercion. Other religions make and keep converts by threatening, rather than by inviting. We do not threaten or coerce because the Bible does not tell us to do so. Our mission is to declare the good news, knowing we cannot change people’s hearts. We pray that the Holy Spirit will do the converting since only He can do it.
When people do believe, we give thanks and glory to the Lord for saving His people. We take no credit since it all belongs to Him.
But what about when people do not believe? First, continue praying and trying. We ought not give up too quickly. But sometimes the person’s resistance is strong, and we are asked not to talk about it any more. In such cases, we are wise to talk to God more about that person than to that person about God. Pray that the Lord would send someone the person will listen to, if he/she will not listen to us. If we still have a relationship with the person, we should watch for an opportunity to speak of Christ again, if it seems the person has become more open.
If and when the person closes the door completely, just pray and leave him/her in the Lord’s hands.