Too bad Ronald Reagan didn't stick with the religion of his Roman Catholic father. Then we could rely on the Vatican to muzzle him the way it is currently moving in on the liberation theologians out of favor with the Curia. Reagan's errancy is using the Bible to make Jesus a militaristic supporter of America's nuclear-arms buildup.

Speaking before the National Religious Broadcasters Conference in Washington, the president told the airwave pastors: "You might be interested to know that the scriptures are on our side in this." He then quoted Luke 14:31 "in which Jesus in talking to the disciples spoke about a king who might be contemplating going to war against another king with his 10,000 men, but he sits down and counsels how good he's going to do against the other fellow's 20,000 and then says he may have to send a delegation to talk peace terms."

At this point, Commander-in-Chief Reagan became the chaplain-in chief: "I don't think the Lord that blessed this country as no other country has ever been blessed intends for us to someday negotiate because of our weakness."

Reagan's flight into scriptural fancy was all that his fundamentalist audience could have hoped for. Many are from the Bible Belt -- as in, if someone doesn't agree with you, get your Holy Bible and belt him with a quote.

That's what Reagan was doing with his Luke 14:31. You're a heretic if you won't turn the Prince of Peace into the Prince of War. Or as the bumper stickers on all those pickup trucks say, "God, Guns and Guts Made America: Let's Keep All Three."

Before the nation bows its head with Ronald Reagan and worships the Golden Nuke, a look at St. Luke's full text is in order. Reagan profaned the meaning of the parable. The next line after the king seeking peace terms because he has the smaller army is this: "So, therefore, every one of you who does not renounce all that he possesses cannot be my disciple."

The text is about the cost of discipleship, in Dietrich Bonhoeffer's phrase. If one is going to follow Christ, it will cost plenty: if there is no renunciation of possessions, don't come. The point of the parable is not that a follower of Christ should get up a bigger army than the Pharisees -- or Soviets -- but that a person should weigh his decisions before making them. By renouncing possessions, a person is free to place total trust in God. In the overall context of Christ's teaching -- and not Reagan's -- the first thing he would renounce is weapons. The last people he would trust are politicians calling for greater militarism.

Being ecumenical in his religious dopiness, Reagan had an error for the Jews. He spoke of "the relevance of religion in the modern world" and referred to "the huge Menorah celebrating the Passover season in Lafayette Park" last December. Reporter Lou Cannon of The Post pointed out that the Menorah is the ceremonial candelabra used during Hanukah.

Reagan's ignorance about Judaism is not new. In October 1983, he phoned an official of the American-Israel Public Affairs Committee to thank him for supporting the administration's efforts to keep the Marines in Lebanon: "You know, I turn back to your ancient prophets in the Old Testament and the signs foretelling Armageddon, and I find myself wondering if -- if we're the generation that's going to see that come about." Armageddon is not in the Old Testament, as Reagan the Bible scholar says. It is in the last book of the New Testament -- Revelations by St. John the Apostle.

Oh, well, what's the difference? Even a president can't be expected to get everything right. It's the idea that counts. But what is Reagan's idea in distorting religion for his own political ends? The Founding Fathers, seeking to protect pluralism, warned repeatedly about the dangers of mixing not only church and state but politics and piety. President John Adams wrote that, "The government of the United States is not in any sense founded upon the Christian religion."

Now, 38 presidents later, here is Reagan using the Bible as a justification for his weapons binge. Perhaps he will get the CIA to use it as the next manual for terrorism in Central America. Reagan cheapens religion with his "God is on our side" sermons.

Religion is honored when it is separated from party platforms and valued for the moral force of faith and hope. It is dishonored when it is Americanized and militarized. Earlier presidents have done one or the other. Reagan is the first to do both.