St. Philip Neri used to say, that he who does not seek, above all things, the salvation of his soul, is a fool.  

How really important is our salvation to us in fact? The true answer to that question is the priority we place on it in our daily decisions and choices. Theoretically, we can hopefully say it is of absolute importance. But the reality of our lives may say otherwise. Yet in fact, there is nothing more crucial in our whole life than after our demise. Will we be with God eternally or alienated from him eternally. St Paul tells us “with fear and trembling work out your salvation. ” (Phil. ii. 12.)

One day St, Ignatius said to Francis Xavier: “Francis, whom do you serve? You serve the world, which is a traitor, that promises, but does not perform. And if it should fulfil all its promises, how long do its goods last? Can they last longer than this life? And, after death, what will they profit you, if you shall not have saved your soul ?" He then reminded Francis of the maxims of the Gospel: "What doth it profit a man, if he gain the whole world, and suffer the loss of his own soul ?"“But one thing is necessary ?" (Luke x. 42.)