During this time he seems to have lived in the family of the then Bishop of Lincoln, and to have been admitted by him to the minor orders of the ministry; for the next thing related of him is that being presented by his father to the united benefices of Sempringham and Torrington he most willingly accepted the charge, and devoted the whole revenue of his livings to charitable purposes. Such was the fervour of his devotion at this time, that it is related that having one day invited one of his companions to join him in his prayers, the youth was so fatigued by the length of the office, and the punctilious care with which Gilbert genuflected whenever the holy names of God and of Christ occurred, that he swore he would never pray with him again.
After a while he was ordained priest by Alexander, Bishop of Lincoln, who held him in such high esteem that he made him his confessor, and would have appointed him Archdeacon; but this Gilbert resolutely declined saying, "that he knew not of a shorter road to perdition."
Persevering in his resolve to give his all to the poor, he now for the first time formally constituted his religious order, by assembling a number of poor girls, amongst them the object of his youthful attachment, whom he made cloistered nuns at Sempringham, and maintained them at his own cost. He next founded a monastery for male religious, to whom he entrusted all the more responsible affairs of the order, providing both nuns and monks with a habit "expressive of humility."
To this time of his life we must probably refer his miraculous escape from death by fire. The story is that a great fire having broken out either in his own house, or in the buildings immediately contiguous, Gilbert remained sitting abstractedly in his window seat, praying and singing psalms; the fire devoured all before it until it reached the spot in which he sat; there its progress was arrested, and the flames died away on every side, leaving the saint and his seat unharmed.
His order continued to expand, many religious flocked to him, and gifts of manors and farms pouring in from all quarters, many monasteries arose under his rule.
The charge of his Order now became so onerous that he is said to have attended the general chapter of the order at Citeaux, in the year 1140, for the purpose of formally resigning his authority. To this, however, his brother abbots refused their consent, and Gilbert returned to his labours, which he was to relinquish only with his life.