"The Church is like a little old grand-mother in a rocking chair -- constant movement without any progress," Krister Stendahl, Frothingham Professor of Biblical Studies, told a Lutheran audience at M.I.T. yesterday.

Speaking on "The Church in the year 2000," Stendahl had the group of Lutheran clergymen and housewives blistering in their seats with his attacks on the Church and on conventional attitudes toward it.

Most people see the Church as the last bastion of tradition and of the good old values, Stendahl said. "Patience is supposed to be the supreme virtue of Christianity." But Jesus, he said, was not a patient man. He was a "pushy man."

The Church must smash the image of religion as a security blanket, Stendahl argued. Otherwise, judging from current statistics, he said, it is obvious that by the year 2000 the Church will not only have nobody to speak to but nothing to say.

Being a Christian will not mean knowing a set of right answers to certain difficult problems, he said. "A Christian should be a guinea pig, and the Church is the laboratory." This is a gruesome policy, Stendahl admitted, especially for the layman who has muddled his way through complexities all week and comes to church to hear some nice, simple principles. "But principles are never practicable," he said.