When a government is against Christians, how should we react according to Bible?

First, we must obey God’s will in all matters. Acts 5:28,29, 33 (NIV),“‘We (the Sanhedrin and the high priest) gave you strict orders not to teach in this name,’ he said. ‘Yet you have filled Jerusalem with your teaching and are determined to make us guilty of this man’s blood.’ Peter and the other apostles replied: ‘We must obey God rather than human beings!’…When they heard this, they were furious and wanted to put them to death.” 

This account illustrates that Christians are always to witness whether by actions or by words for that is God’s will. Where governments outlaw our message, our loving Christian behaviors might be the initial witness. Some, seeing our example, may be drawn to ask us about our beliefs. Additionally, we may leave printed tracts in public places. If and when God opens an opportunity to proclaim His truth, we should joyfully share the Gospel. 

Prison did not stop Paul from preaching. After he was beaten, chained, and put in a cell, Paul and Silas sang hymns.  Acts 16:25(NIV), “About midnight Paul and Silas were praying and singing hymns to God, and the other prisoners were listening to them.” An earthquake opened the prison but Paul did not escape. His behaviors were so amazing that the prison guard asked, “‘Sirs, what must I do to be saved?’ They replied, ‘Believe in the Lord Jesus, and you will be saved—you and your household.’ Then they spoke the word of the Lord to him and to all the others in his house.” Acts 16:30-32 (NIV). The guard and his family were converted!

However, we do not need to purposely put ourselves in danger. Acts 9:19-25 (NIV), “Saul (later named Paul) spent several days with the disciples in Damascus. At once he began to preach in the synagogues that Jesus is the Son of God…After many days had gone by, there was a conspiracy among the Jews to kill him, but Saul learned of their plan…But his followers took him by night and lowered him in a basket through an opening in the wall.” Thus, the local Christians secreted Saul out of danger.

Jesus also instructed His followers to leave hostile towns in Luke 9:5(NIV), “If people do not welcome you, leave their town and shake the dust off your feet as a testimony against them.” Remember, now is not the time for the conversion of the world. The world will receive God’s word during Christ’s millennial reign, “for the earth will be filled with the knowledge of the LORD as the waters cover the sea.” Isaiah 11:9(NIV). 

In some nations, Christians meet secretly at night in the forests or in other houses. Over the centuries, Christians have secretly printed the Bible and truth literature. Even in hostile countries, Christians will obey God, not man. But we need to be wise in our behaviors.