We desire things and persons in this world because all things were created by God good in themselves.
We desire food, shelter, clothing, a sunny day, sex, love, achievement, long life, a book, a new dress, a computer et., in other words, we entertain countless desires. Some of these desires help us to sustain life in this world. We also have a boundless desire to be happy. Some seek to be happy by a constant acquisition of material goods, but soon discover that this cannot bring complete happiness. Some seek power over others in this world but misfortune and death takes it away. Others seek it in sex but it also ultimately fails to satisfy. God has given us a desire for endless life because he meant for us to live forever, however, death teaches us that this desire cannot be achieved in the present life. We desire truth and beauty which is good, but human bodily beauty is deceptive because it is lost by age, sickness and death. We search for ultimate truth in science and philosophy, tut they are not in these because truth is a person. The humanist seeks to serve God by serving man. If in the process he forgets God, it will be to no avail. God's Commandment is first to love God and second your neighbor.
Christ was tempted the devil to gain notoriety by changing stones into bread, by dazzling the people by casting himself off the top of the temple supported by angels and finally to gain all the kingdoms of the world by worshiping Satan. He rejected all these temptations and warns us, "What does it profit a man if he gains the whole world and loses his own soul". (Mk 8:6)
There is in the soul a desire for absolute goodness, beauty and truth which the psalmist expresses in this way:
Why does the first commandment tell us to love God first and above all things? Because we have a tendency to love creatures which is ourselves above God. Our inclination to love lures us toward sensible realities such as food, drink, sex, family, power, bodily comfort and even bodily immortality. If we follow any one to these, they become all absorbing and in the process we think less and less about God and spiritual realities become distasteful and repulsive. We loose the desire to pray or read any spiritual books. In other words our consciousness becomes immersed and entangled in temporal realities which ultimately lead to temporal and eternal unhappiness because our hearts is made for God and only He can fulfill our infinite desire to be happy.
St. Augustine tells us that "The love of temporal things is not extinguished except by the sweetness of eternal things." To acquire a taste for divine realities requires discipline. This means daily prayer and contemplation and to achieve this end nothing is better than the daily praying of the Psalms. The daily recitation of the psalms teach us how to pray. In time we will experience a deeper communion with God which will bring us true happiness. And of course, must never forget to offer the Sacrifice of Christ. If anything become more important than participating in offering Christ's sacrifice, we are deluding ourselves.