Availability and love were the distinctive marks that Saint Michael sought to imprint on his religious community of 1835. This is the double movement which, in his opinion, must animate the vocation of all Christians. Hence, it was to be the guiding light of the newly constituted Priests of the Sacred Heart:

"Oh! If only we could gather together a society of priests having for their programme the very programme of the Heart of Jesus…. Absolute generosity and obedience, perfect simplicity, unchanging gentleness! ... To exert the immensity of charity in the limits of their position… imitating Mary, the Servant of the Lord."

In 1838 Michael introduced to his community, ad experimentum, the summary of the Constitutions of the Society of Jesus. His originality, however, is found in the prologue he wrote to them, the Manifesto: the true founding document of the religious family of Betharram, which contained his own specific Charism.