Arrived at manhood, Nicolas married a virtuous young girl, named Dorothea Wysyling. They had ten children, five sons and five daughters.
Nicolas was himself unanimously elected governor and judge of Obwalden. The high dignity of Landaman was decreed him by the general assembly several times; but he feared the great responsibility; and, without doubt, he felt also that God had reserved him for some other and greater thing.
Nicolas had thus lived fifty years for the good of his country and family, and esteemed by all, when, in the year 1467, he felt himself drawn to a closer walk with God, in a life of entire separation from the world. His eldest son, John von der Flue, thus speaks of him: "My father always retired to rest at the same time as his children and servants; but every night I saw him rise again, and heard him praying in his chamber until morning. Many times, also, he would repair in the silence of the night to the old church of S. Nicholas, or to other holy places." These hours of solitude were to him the happiest moments of his life; and the interior impulse became even more powerful to consecrate the remainder of his life to the devout contemplation of eternal truths. God also favoured him frequently with miraculous intimations of His divine will. On one occasion, when he went to visit his flock at a place called Bergmatt, according to his wont, he knelt upon the grass, and began to pray, when God vouchsafed him a consoling vision. He beheld a fragrant lily, white as snow, come out of his mouth, and rise towards heaven. Whilst he regaled himself with the perfume and beauty of the flower, his flock came gambolling towards him, and amongst them a noble horse. As he turned to look, the lily inclined itself towards the horse, which advanced and drew it from his mouth; by which Nicolas was made to understand that the treasure to which he should aspire was in heaven: and if his heart was not wholly detached from the things of earth, he would forfeit the possession of the celestial joys reserved for him.
Another time, while engaged in the ordinary business of his house, he saw three men approach him, of venerable aspect, one of whom addressed him thus:—
"Tell us, Nicolas, wilt thou put body and soul into our power?"
"I give myself to none," replied he, "but the Almighty God, whom I have long desired to serve with my soul and body."
At these words the strangers turned with a smile one towards the other, and the first answered: "Because thou hast given thyself wholly to God, and art bound to Him for ever, I promise that in the 70th year of thine age thou shalt be delivered from all the troubles of this world. Remain constant in thy resolution. Thou shalt bear in heaven a glorious banner amidst the armies of God, if thou hast borne with patience the cross that we lay upon thee."
Upon this the three men disappeared. These visions confirmed him in his resolution of separating from the world. He disclosed to his wife the desire of his soul, and entreated her, for the love of God, to give him permission to fulfil this vocation. She consented with calm resignation, and Nicolas began at once to arrange the affairs of his house, assigning to each of his children his part of the inheritance. He then assembled all his household,—his old father, 70 years of age, his wife, his children, and his friends; he appeared before them barefoot and bareheaded, clothed in the long robe of a pilgrim, with a staff and chaplet in his hand; he thanked them for all the kindness they had shown him, exhorted them for the last time to fear God before all things; then he gave them his blessing, and departed. That this separation was a trial to him, was evidenced by his frequent expressions of thankfulness to God that He had strengthened him to overcome for His service the love he bore to his wife and children.
Nicolas set out with a tranquil heart for the place which God had chosen for him. Crossing valleys and mountains, he arrived at the limits of the Confederation. When not far from Aarau, at a spot whence he could see beyond the frontiers the little town of Liechstall, he had a remarkable vision. The town, with its houses and towers, appeared to him enveloped in flames. Terrified with this spectacle, he entered into conversation with a peasant whom he found in a neighbouring farmhouse, and made known to him his purpose, begging him to point out a solitary spot where he might be able to carry it into effect. This man counselled him to remain in his own country; because, as the Confederates were not always well received in other parts, he might be unfavourably regarded, and his retreat be disturbed. Brother Nicolas thanked his host for this good counsel, and turned his face again towards home. He rested not till he reached Melchthal, his native place; where he repaired to one of his pastures called the Kluster. There he made a little hut of branches and leaves under a larch tree, in the midst of thorny bushes, and remained without discovery till the eighth day, neither eating nor drinking, but absorbed in prayer. Some hunters in pursuit of game first became aware of his retreat, and spoke of him to his brother, Peter von der Flue, who visited him, and besought him not to suffer himself to die of hunger in so wild a solitude. Brother Nicolas assured him that he need be without uneasiness on his account, as he had experienced no evil result up to that time. Nevertheless, that he might not seem to tempt God, he sent secretly for the curé of Kerns, named Oswald Isner, and acquainted him with the whole case. This good man gave the following testimony after the hermit's death, as may be read in the parish record of the year 1488:—
"When Bro. Nicolas had passed eleven days without food, he sent for me, and asked me whether he should take some nourishment or continue his trial, as he had always desired to be able to live without eating, in order that he might be more effectually separated from created things. When I saw that this could come only from the source of divine love, I counselled Bro. Nicolas to persevere as long as he was able; and from this time to the day of his death, a period of more than twenty years, he continued to dispense with bodily food. As the pious brother was more familiar with me than with any other person, I sought earnestly to learn from him how his strength was sustained; and one day he told me, in great secrecy, that when he assisted at Mass, and the priest communicated, he received a strength which enabled him to refrain from all other nourishment."