There was no "room at the inn" when "St. Mark's Gospel" sought a Washington booking this fall but perhaps when Alec McCowen returns to America in the spring a stage will be found. Arena's Kreeger or Ford's would be ideal.

Seen recently in New York and now on a brief tour which will include Cleveland, Minneapolis, Aspen and St. Louis, McCowen's reading of the shortest gospel will return for another three-week visit to New York next month. It's already sold out, as 250-seat Marymount College Theater on the Upper East Side.

This is one of the most extraordinary stage experiences of anyone's life. Informally dressed in slacks, jacket and an open, tieless shirt. McCowen simply reads words first published 367 years ago: "The Gospel According to St. Mark" in the King James or "authorized," version of the Bible.

In his superb voice of commanding clarity, McCowe breathes vitality into the familiar words, relating the story of Jesus as though it's just happened. Mark becomes an eyewitness enthusiastically telling friends about the miracles he has seen. He is excited about his experiences and as he says, wants to pass along "the good news."

There is unexpected humor in this gospel: McCowen'eyes widen in astonishment as he tells how, several times, the multitudes were fed from a few loaves and fishes. Mark has several version of this and actor uses them to underline his amazement. When a rough sea arises and Jesus walks on the water. McCowen's feet follow a single stage board with tentative, then stronger steps.

McCowen remains purely the actor delighting in his rich material, avoiding any trace of evangelical passion. His actions, garb and even the bright lighting wholly avoid solemmity. "I try for a feeling of sunshine," he says, "and if I had a symbol for Christianity it would be of a man rolling up his sleeves, not nailed to a cross."

The result is that one hears the familiar words as if for the first time, tasting their heady conviction and carthy source. In his brief introduction, McCowen quotes scholar F. P. Coleman as noting that "Mark is the nearest we have to an eyewitness of the life of Jesus."

One wonders what the effect on clergymen might be experiencing McCowen's reading. Will some take the actor's cue of simplicity, savoring words and phrases for fresh insights, discovering the humor as Mark alludes to the first disciples?

To do so would require the physical freedom the actor gains by having memorized the complete text, a task which took, he says, 16 months by learning three verses a day. Not being chained to a lectern and with his eyes freed from looking down to the printed words, McCowen frees not only himself but the gospel as well.

Best known in America for appearances in "Hardrian VII," "The Misanthrope" and "Equus," McCowen has found a "one-man show" which takes the curse off an overworked mime. This first American visit cannot be extended. He has a Dec. 18 date to present his discovery in West-minister Abbey. But his American producers, Arthur Cantor and Greer Garson, hope that on his springtime return to America Washington will have a stage for him.