At some point around A.D 150-155, Justin Martyr writes one of the first Christian apologetic letters ever, aptly called his “First Apology”, to the Roman Emperor Pius, his sons and to the Roman Senate. He appeals to their philosophical senses, and to their reason and logic, to give Christianity an unbiased review and to stop persecuting the Christians. Justin points out that Christians are judged guilty simply by admitting to being a Christian, and that to be found guilty of something without a proper trail is no way to properly serve justice.
Justin includes in this a letter a long apologetic of Christianity, touching on a varied selection of beliefs and reasons for what the Christians were doing. One area explained was the Christian’s search for a kingdom. Justin explained how this search did not involve an earthly kingdom but a heavenly one, so no threat should be felt from this. The emperor should even welcome Christians because they are a people of peace and honor, not a violent and lawbreaking people. Concerning lawbreaking, Justin uses the incident when Jesus responded to the Pharisees question about paying taxes, “Is it right to pay taxes?” Jesus looked at the picture of Caesar on the coin and said, “Give to Caesar what is Caesars, and to God what is Gods.” Justin used this to illustrate that Christian are commanded to obey civil laws and not to be disobedient.
Justin then liberally quotes from the scriptures; particularly what Jesus said concerning such things as lust and adultery, forgiveness of others, swearing, and the godly way in which to treat others. He attempts to establish the validity of Jesus as the Christ by introducing the prophets of the Old Testament. He uses the prophetic writings of the Jews as proof of the deity of Jesus, using prophets that Pius may have heard of, like Moses and Isaiah. He joins history to the prophecies to prove them true; for example, he quotes the prophecy of Jesus’ birthplace by Micah, he then points out the registers of taxes in Judea as a means of verifying this prophecy. Justin mentions the destruction of Jerusalem and how it was predicted long before it happened; this prediction was by the same prophets who predicted the coming of Jesus. The fulfillment of the destruction of the Jerusalem prophecy should be a sign that the Jesus prophecies are also true.
Justin warns Pius of the consequences of not doing the right thing, which is being brought under the awesome judgment of an almighty God. He also mentions a letter written by Pius’ father, the Emperor Adrian, which basically said to punish men for breaking the law, but not for just being Christians. Unfortunately, the persecution of early Christians continued for another 150 years until Constantine legalized Christianity in 313.