Obedience could be the easiest virtue to describe, but the toughest to live. Obedience is simply conforming our lives to the will of God, submitting ourselves to His plan: the way it is expressed in the Holy Bible, in the Traditions and the teachings of the Church, in Natural Law, in the directions of our superiors and parents, in the dictates of a well-formed conscience, and in the prompting of the Holy Spirit interpreted prudently in discernment.
In St. Paul's letter to the Hebrews, he teaches about the obedience of Christ (5:8-10): "Son though He was, He learned obedience from what He suffered; and when He was made perfect, He became the source of eternal salvation for all who obey Him." Again in Psalms we read: "If today you hear his voice, harden not your hearts."
When God created the first parents, God expected them to practice obedience in their lives.  The only virtue He asked of them was obedience.  All sin came into the world through disobedience, through acts of willfulness and pride.  Everyone suffers because of the first parents' disobedience.  Our forefathers suffered because of the disobedience of Adam and Eve.  We suffer and our children will suffer in generations to come.  Montaigne, the French philosopher, remarks, "The first law that ever God gave to man was a law of obedience.  It was a commandment, pure and simple... From obedience and submission spring all the other virtues, as all sin does from self-opinion and self-will." St. Irenaeus, one of the early Fathers wrote: "The seduction of a fallen angel drew Eve, while the glad tidings of the Holy Angel drew Mary to begin the plan which would dissolve the bonds of the first snare."  Jesus shines like the most perfect obedient son. His early life was hidden within obedience.  As St. Paul rightly puts it, "Though he was in the form of God, he did not regard equality with God something to be grasped. Rather, he emptied himself, taking the form of a slave, coming in human likeness; and found human in appearance, he humbled himself, becoming obedient to death, even death on a cross. (Phil. 2:6-8) 
The martyrs of Rome, by their example, converted thousands who came to watch them die.  The crowds expected to see frightened, shackled, and depressed slaves forced to their deaths.  Instead, they saw courageous, confident, free, joyful men and women, more liberated than their persecutors, people whose obedience to God freed them from all earthly trepidations, compromises, and doubts.  St. Philip Neri preached about obedience: "Entire conformity to the divine will is truly a road on which we cannot go wrong, and it is the only road that leads us to taste and enjoy the peace which sensual and earthly men and women know nothing of."
Some people may say, "My problem is not obeying God's will. My problem is finding out what it is!"  The process of discovering God's will for you is called discernment.
The spirit of discernment and obedience to God's will

can be acquired through silent prayer and mediation.  We cannot be obedient to God's will unless there is a period of prayer everyday. The habit of prayer must be developed, cultivated. We cannot know God's will unless we pray.  Achievement and success in life cannot happen without inner peace.  Peace is born of prayer, especially the prayer to the Holy Spirit for light, inspiration, and courage. "Come Holy Spirit, enkindle in me the fire of love."
There are different types of prayer through which we can discern the will of God: mental prayer, active prayer, and passive prayer. Through mental prayer,we learn to listen to the will of God in our life. Another way to discern the will of God is through active prayer like daily Mass, the divine office, the rosary, spiritual readings, devotional prayers, or a quick visit to the Blessed Sacrament. The third type of prayer is passive prayer. In passive prayer we do nothing but open ourselves to Our Lord's inspiration. This is called contemplation. We listen to the voice of the Lord, experience His presence, and absorb His love, grace, and mercy.  Obedience to God's will takes place when we listen to Him in prayer. Usually in prayer, we do the talking and God does the listening!
"Never ask for an assignment and never ask to get out of one, or you'll regret it." This adage is especially true in the life of a priest.  Every priest takes the vow of obedience.  They are obedient to the bishop and their superiors.  A priest is obedient to the priesthood. A priest is always faithful to the priestly call; faithfully and generously obeying the expectations of the people to whom they minister.  Priests foster and strengthen their priestly identity and avoid anything or anybody that can threaten it. Finally, they are obedient to suffering. "Son though He was, He learned obedience through suffering."
Very often, obedience causes suffering and painful experiences in our life. At that time, we should be one with our Eternal High Priest,  "Father, let this cup pass, but not my will but thy will be done." St. John Vianney, whose feast day was August 4, preached: "Obedience makes the will supple. It gives the power to conquer self, to overcome laziness, and to resist temptations."
Obedience is the virtue through which we can pursue holiness, humility, simplicity, and charity because we are attentive to the will of God and obedient to His designs. We know this is what God wants. In obedience, we conform to our Lord who was obedient until death, even death on the cross. We place our plans, our desires, and our will at the disposal of the Father.