In Acts 4 the leaders of the Temple call Peter and John and question them regarding the miracle performed. Of course they couldn't say anything against them, since the man who was healed was standing them with them, but they nevertheless insisted that they no longer preach about Jesus Christ's resurrection (v. 18).
Peter and John's answer, however, is a classic one: "Whether it is right in God's sight to listen to you rather than to God, you must judge; for we cannot keep from speaking about what we have seen and heard" (vv. 19-20). It wouldn't be the first time the Temple rulers put themselves against God and his word -- they had done that countless times during Jesus' own ministry -- and it wouldn't be the last.
Then the apostles regroup and pray to God in light of the threats they received. Among other things, they pray as follows:
And now, Lord, look at their threats, and grant to your servants to speak your word with all boldness, while you stretch out your hand to heal, and signs and wonders are performed through the name of your holy servant Jesus (vv. 29-30).
Here we get a nice example of the warfare of the apostles, so to speak; or perhaps better, the warfare in which the kingdom of God engages against the evils of the world. They don't pray for fire from heaven this time around; they don't pray that their opponents be stricken dead. While the authorities and rulers threaten beatings, violence, and murder, the soldiers of God's kingdom confront the powers that be with nothing more than faith in God, boldness in the Holy Spirit to preach the message of Christ, and miraculous deeds which give life to the dead.
In fact the apostles in Acts are regularly nonviolent, and oftentimes the victims of extreme violence. Stephen, for instance, as he is being stoned to death, prays to God that he not hold the sin of his murder against his murderers. Importantly, they are all like this because they are strengthened by the Holy Spirit (4.31, 6.5): the Holy Spirit of God present in them transforms them to embody the nonviolent fruit of the Spirit, such as love, peace, forbearance, kindness, gentleness (Gal 5.22-3).
This is what Christian ministry, and indeed Christian life, ought to look like: a nonviolent war waged against the forces of darkness wherever they may be, a war that by the power of God is life-giving, even if we die in the meantime.