--- (AP) _ While the crowd in the lecture hall awaited the appearance of renowned theologian Karl Barth, someone scrawled on the blackboard behind the podium: ''God is other people.''

The rumpled, bespectacled Barth ambled onto the stage and paused, staring at the words. With a twinkle in his eyes, he picked up the chalk and added a comma, making the sentence read:

''God is other, people.''

That total ''otherness'' of God, beyond any human calculation or ingenious devising, launched the thunderbolt flung by the great Swiss scholar into the arena of 20th century theology.

''Only God speaks well of God,'' Barth declared, contending that any human attempts to conceive or define him is to reduce divinity to human dimensions, choices and control, a false idol.

''Let God be God,'' he said.

Barth (pronounced Bart) is regarded by many as the century's preeminent Christian thinker, boldly original, penetrating, thorough, trenchantly gripping, a master in his field.

He is one in an extraordinary line of theological titans who crossed the world's stage this century and changed the landscape of religious thought.

Among them were Barth's Swiss compatriot, Emil Bruner; the German martyr to Nazism, Dietrich Bonhoeffer; the Roman Catholic ''incarnationalist'' Karl Rahner; the ''demythologizing'' Rudolf Bultmann; Judaism's ''relationist'' Martin Buber; the existentialist Paul Tillich, and Christian ''realist'' Reinhold Niebuhr.

These modern religious giants all are dead, and, as the century draws to a close, it's almost as though some special dispensation has ended. But their work, both emulated and criticized, permeates the religious world.

To Barth, the remoteness of a ''wholly other'' God constituted his stern ''No'' to a sin-darkened world.

Trying to know anything about God through reasoning, nature, sentiments or philosophical arguments is vain and benighted, Barth said, reflecting humanity's original revolt by trying itself to ''be as God.''

''It is the attempted replacement of divine work by human manufacture,'' Barth said, an effort to ''divinize man and to humanize God with romantic formulations'' so as to ''wipe out the distance between them. ...

''God is not to be sought out in his inscrutable loftiness.''

However, Barth said, God took the initiative to turn that overshadowing ''No'' into a ringing ''Yes'' through the work of Christ and the ''Word of God.''

''And so,'' he said, ''his inevitable 'No' is always enclosed in his primary 'Yes' to man.''

Barth called Christ both ''God's man'' and ''man's God,'' and said:

''In the midst of his people, God lets one become man, espousing totally the cause of this man,'' attesting identity with him, thus enacting ''community with man'' and exalting man to ''community with him.''

Barth, who died in 1968 at age 82, belonged to the Swiss Reformed Church, but his powerful, free-thinking scholarship carried weight not only throughout Protestantism but also in Catholicism, with whose thinkers he maintained a running dialogue.

In the scholarly world, Barth's approach became known as ''neo-orthodox'' or ''Barthian,'' a term he deplored. He called his work ''evangelical theology.'' It is firmly, steadily rooted in Scripture.

''The biblical witnesses are better informed than are the theologians,'' he said. ''For this reason theology must agree to let them look over its shoulder and correct its notebooks.''

For all his immense erudition and analytical skills, the pipe-smoking Barth had a kindly, cheerful disposition and whimsical, self-effacing wit, seeming to take himself much less seriously than did some of his colleagues.

''The theologian who has no joy in his work is not a theologian at all,'' he said. ''Sulky faces, morose thoughts and boring ways are intolerable in this science.''

He had a zest for history, literature, music and detective stories. Once, fretting about whether he would be understood in some 1962 lectures in the United States, he remarked, ''My English is criminal because I learned it by reading detective stories.''

Tender and gruff, modest but assured, he rode horseback, sang loudly - ''like a lion,'' as a son put it - preached regularly to penitentiary prisoners and began his days listening to Mozart.

''It may be that when the angels go about their task of praising God, they play only Bach,'' he said. ''I am sure, however, that when they are together en famille, they play Mozart and then, too, our dear Lord listens with a special pleasure.''

Besides Barth's driving theological work through a score of books, including his 12-volume ''Church Dogmatics,'' and in lectures around the world, he led efforts for Christian unity and to forge church resistance to the Nazis.

The church ''would do better to become a tiny remnant and flee to the catacombs than to make peace with this terrible doctrine in any way,'' he said of Nazism.

Barth, then teaching in Bonn, Germany, helped to form the Confessing Church, a minority wing opposing Hitler's policies, and to organize the 1934 meeting that issued the famed Barmen Declaration, blasting attempts to subordinate the church to Hitlerism.

Shortly thereafter, Barth was expelled for refusing to take an oath of allegiance to Hitler or begin classes with the customary ''Heil Hitler.''

He hurled his blunt ''No'' to human presumptions about understanding God at a time when Christian liberals believed scientific progress and education would gradually help achieve paradise on Earth - a notion shattered by the horrors of war and totalitarianism.

''The final root and basis of all human disorder is the dreadful, godless, ridiculous idea that humanity is the Atlas to hold up the vault of heaven,'' Barth told the 1948 founding assembly of the World Council of Churches.

Nevertheless, he said, God ''is no lonely God, self-sufficient and self- contained.''

Rather, he freely chooses through Christ to be the ''God of man,'' Barth said. ''He exists neither next to man nor merely above him, but rather with him, by him, and most of all for him.

''A God who confronted man simply as exalted, distant and strange, that is, a divinity without humanity, could be only the god of ... 'bad news' instead of the 'good news.' ... He would be the god of a scornful, judging, deadly 'No.'''

However, Barth said, ''the content of God's word is his free, undeserved 'Yes' to the whole human race, in spite of all human unreasonableness and corruption.''

Jesus ''exposes the gulf which separates God and man and by exposing it, bridges it,'' Barth said, leaving humanity ''swamped by grace.''

Barth rejected biblical literalism, contending the Bible was not verbally infallible since everything human, including language, is limited and faulty.

Yet he saw Scripture as the medium elected by God as the most suitable within man's restricted sights for extending ''God's word'' to humanity.

In a conversation with Barth, fellow Swiss theologian Emil Bruner once raised the point that some of the Bible seemed profane.

''Nonsense, it's all profane 3/8'' Barth retorted. ''The Bible was written by very profane men. But, and this is the distinction, they were profane men in conversation with God.''

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