Lawrence Petersen, Olaf’s brother, professor of theology at Upsala, was a man of grave and gentle character. Conscience ruled in both the brothers. To Olaf she gave courage to prefer her behests to the opinion of those whom he most highly esteemed; while Lawrence obeyed her secret voice, especially in the discharge of his daily duties. He fulfilled his functions with great punctuality. The charity which breathed in all his actions and all his words won the hearts of men. He made his students acquainted with the Bible; he taught them to preach in conformity with Scripture, and not after the traditions of men. But notwithstanding the rare nobleness and candor of his character, the enemies of the Gospel hated him. Gustavus who, in 1527, had given him a proof of his satisfaction by naming him perpetual rector of the university, was now about to confer on him a still higher dignity.
Archbishop Magnus had vacated his archiepiscopal see; it was therefore necessary to fill it up. The king consequently called together at Stockholm, on St. John’s Day, 1531, a large number of ecclesiastics. The chancellor Anderson requested the assembly to take into its consideration the choice of a new archbishop, imposing at the same time the condition that he should be a man thoroughly established in evangelical doctrine. The assembly pointed out three candidates—Sommer, bishop of Strengnaes; Doctor Johan, dean of Upsala; and Lawrence Petersen. It then proceeded with the definitive election, and on the suggestion, as it seems, of Gustavus, Lawrence obtained one hundred and fifty votes, and was therefore elected. The king testified his complete satisfaction with the result. The question might be asked, how was it that their choice did not fall on Olaf, who was the principal reformer? The assembly, doubtless, was unwilling to remove him from the capital. Lawrence’s long residence at Upsala qualified him for this high dignity; and perhaps the Scripture saying, ‘A bishop must be temperate,’ caused the preference to be given to his brother. The king handed to Lawrence a costly episcopal crosier, saying to him, ‘Be a faithful shepherd of your flock.’ The old proverb, ‘Wooden crosier, golden bishop; golden crosier, wooden bishop,’ was not to be applicable in this case.