We usually chafe at the idea of discipline, but it's vital to train well for the spiritual life. Due to Original Sin, we are not naturally inclined to love God - thus, we must be taught, through prayer and self-denial and generosity, how to learn to love. But this discipline is difficult, and many people choose not to engage in it - which is why Our Lord calls salvation "a narrow gate". We must not be afraid to train for the everlasting life to which we are called!