97 Consequently, it is clear that the revelations made to St. Margaret Mary brought nothing new into Catholic doctrine. Their importance lay in this that Christ Our Lord, exposing His Sacred Heart, wished in a quite extraordinary way to invite the minds of men to a contemplation of, and a devotion to, the mystery of God's merciful love for the human race. In this special manifestation Christ pointed to His Heart, with definite and repeated words, as the symbol by which men should be attracted to a knowledge and recognition of His love; and at the same time He established it as a sign or pledge of mercy and grace for the needs of the Church of our times.
Source: Haurietis Aquas (Vatican.va)