The new pope, John Paul I, yesterday enchanted several hundred thousand onlookers jammed into St. Peter's Square with his direct and modest style.

In the first of the brief sermons he will preach each Sunday from the balcony of St. Peter's Basilica, John Paul told of his surprise and fear at his election.

"Yesterday morning I came to the Sistine Chapel to vote tranquilly," he said, "but I never imagined what was to follow. As soon as the danger began for me, two colleagues near me reassured me with words of courage."

"One said to me, 'Courage. If God gives you a burden, He also gives you help to carry it.' And another colleague said, 'don't worry. In all the world there are so many people who pray for the new pope.'"

A Vatican spokesman announced that the pope's coronation will take place next Sunday.

Dressed in a white skull cap and white cassock, John Paul did look like a frail figure from below, and the crowd audibly sighed with him. The more acute must have noticed that during the sermon he used the pronoun "I" and not the regal "we" frequently employed by supreme pontiffs.

He went on to tell brief anecdotes of his personal involvement with John XXIII and Paul VI, his two predecessors and the sources for his name.

"Obviously," John Paul said, "I have not the wisdom of the heart of Pope John nor the training and culture of Pope Paul. But I am here in there place so I have to try and serve the church. I hope you will help me with your prayers."

Then the new pope blessed the huge throng and many chanted the Latin responses back to him. The prayer over, he waved and sone cried in delight, "eh pa-pa, eh pa-pa."

The Swiss Guards, with pikes, red-plumed helmets and baggy, orange and blue striped uniforms, marched. An army brass band played. The bells of St. Peter's pealed and the great crowd left the embrace of the twin colonnade.

Earlier, in a televised address from the Sistine Chapel where he was elected on Saturday, the pope carefully underscored the twin traditions he intends to embody.

On the Johnian side, he sent greetings to all suffering from economic, political or natural disaster. On the Pauline side, he repeated his opposition to contraception asserting that it leads to the dehumanization of man, to abortion and even to collectivization. He said he prayed that families "may be defended from the destructive attitude of sheer pleasure-seeking which snuffs out life."

The Johnian style message was sweeping. "We want to send a special greeting to all those who are suffering at this moment," the pope said. "To the sick, to prisoners, to the exiled, to the persecuted; to those who have no work or encounter difficulties in the hard struggle for life; to those who suffer for the constrictions placed against their Catholic faith, who are unable to freely practice his faith without losing their basic rights as free men and citizens."

"We think in particular of the martyred land of Lebanon, of the situation in the land of Jesus, of Sahel, of India, and of all those sons and brothers who suffer painful deprivation as a result of social and political conditions and because of natural disasters."

Like Paul, the new pope walked a careful line on efforts to achieve union with other faiths. He said he favored ecumenism "without doctrinal retreats but also without hesitation."

He gave some support for moves to share power with bishops but indicated that he, like Paul, would have the last word. The movement evolved from the Second Vatican Council, held from 1962 to 1965, a body that also produced approval to deliver the liturgy in common speech. John Paul said he will "devote all our ministry" to the councils teachings.

One of the keenest observers in Vatican City, Father Francis X. Murphy, a Redemptorist priest who frequently writes in lay publications, said that John Paul can't be labeled easily.

"He is saying that there is no more right and no more left," Murphy remarked, "because he took the names of John and Paul."