To be stern with oneself, means to subject ourselves completely to God's will, without any reservations. Many a times, we find a good excuse to switch to "something better", when we are faced with spiritual aridity/boredom. The resolutions of prayer we take, become too dry to execute. But true Christian spirituality has always been more about a commitment and consistency, and less about "how I feel". Our good Lord never gives us a suffering which we can't handle. His grace always supports our life. Let's trust Our Lord more.
______________________________________________________ "Be gentle to all, but stern with yourself"