For Catholics, the new Liturgical Year commences with the first Sunday of Advent. In this new liturgical year, the Church not only wishes to indicate the beginning of a period, but the beginning of a renewed commitment to the faith by all those who follow Christ, the Lord. This time of prayer and path of penance that is so powerful, rich and intense, endeavors to give us a renewed impetus to truly welcome the message of the One who was incarnated for us. In fact, the entire Liturgy of the Advent season, will spur us to an awakening in our Christian life and will put us in a ‘vigilant’ disposition, to wait for Our Lord Jesus who is coming.
The word "watch" is repeated several times in the short passage near the end of Mark's Gospel.  Here Jesus compares "the watch" to the work of a gatekeeper who vigilantly remains alert  at the door for his master's return.  But what is the attitude of the gatekeeper, and what is the nature of his watch?  Is it one of fear at what his master might find when he comes home?  Or is it one of great  expectations, in which the gatekeeper is focused on a grand and celebratory return? Certainly, the true Christian attitude is the latter.
While He is forecasting His return in glory,  Jesus also needs His friends to be by His side and to follow Him faithfully to the cross.  Throughout Mark's Gospel, the ones Jesus chose to be His disciples fail to understand what watching is all about; they fail to see Jesus for who He truly is.  Thus, He orders them sternly to watch, to keep alert, and to be ready when their service is needed.
Yet, we know that these are the men whom Jesus will find sleeping in the garden  during His trial with agony and prayer. 
The season of Advent is designed to be a time of fine-tuning our Christian attitude of hopeful, joyful watching.  In the Northern Hemisphere, these days of waiting correspond to the darkest days of the year, a time that lures the human body into sluggishness.  Yet, that is not the posture of the Christian community.  We are to hear and obey the summons of the Lord to be alert and watchful.  Our watching constitutes yearning for a world renewed by God and made perfect by His love and mercy.  Using our gifts for others is the best way to stand ready and alert.