The seven gifts of the Holy Spirit are enumerated in Isaiah 11:2-3. They are present in their fullness in Jesus Christ but are found in all Christians who are in a state of grace. We receive them when we are infused with sanctifying grace, the life of God within us—as, for example, when we receive a sacrament worthily. As the current Catechism of the Catholic Church notes, "They complete and perfect the virtues of those who receive them." Infused with His gifts, we respond to the promptings of the Holy Spirit as if by instinct, the way Christ Himself would.
Wisdom is the first and highest gift of the Holy Spirit, because it is the perfection of faith. Through wisdom, we come to value properly those things which we believe through faith. The truths of Christian belief are more important than the things of this world, and wisdom helps us to order our relationship to the created world properly, loving Creation for the sake of God, rather than for its own sake.
Understanding is the second gift of the Holy Spirit, and people sometimes have a hard time understanding (no pun intended) how it differs from wisdom. While wisdom is the desire to contemplate the things of God, understanding allows us grasp, at least in a limited way, the very essence of the truths of the Catholic Faith. Through understanding, we gain a certitude about our beliefs that moves beyond faith.
Counsel, the third gift of the Holy Spirit, is the perfection of the cardinal virtue of prudence. Prudence can be practiced by anyone, but counsel is supernatural. Through this gift of the Holy Spirit, we are able to judge how best to act almost by intuition. Because of the gift of counsel, Christians need not fear to stand up for the truths of the Faith, because the Holy Spirit will guide us in defending those truths.
While counsel is the perfection of a cardinal virtue, fortitude is both a gift of the Holy Spirit and a cardinal virtue. Fortitude is ranked as the fourth gift of the Holy Spirit because it gives us the strength to follow through on the actions suggested by the gift of counsel. While fortitude is sometimes called courage, it goes beyond what we normally think of as courage. Fortitude is the virtue of the martyrs that allows them to suffer death rather than to renounce the Christian Faith.
The fifth gift of the Holy Spirit, knowledge, is often confused with both wisdom and understanding. Like wisdom, knowledge is the perfection of faith, but whereas wisdom gives us the desire to judge all things according to the truths of the Catholic Faith, knowledge is the actual ability to do so. Like counsel, it is aimed at our actions in this life. In a limited way, knowledge allows us to see the circumstances of our life the way that God sees them. Through this gift of the Holy Spirit, we can determine God's purpose for our lives and live them accordingly.
Piety, the sixth gift of the Holy Spirit, is the perfection of the virtue of religion. While we tend to think of religion today as the external elements of our faith, it really means the willingness to worship and to serve God. Piety takes that willingness beyond a sense of duty, so that we desire to worship God and to serve Him out of love, the way that we desire to honor our parents and do what they wish.
The seventh and final gift of the Holy Spirit is the fear of the Lord, and perhaps no other gift of the Holy Spirit is so misunderstood. We think of fear and hope as opposites, but the fear of the Lord confirms the theological virtue of hope. This gift of the Holy Spirit gives us the desire not to offend God, as well as the certainty that God will supply us the grace that we need in order to keep from offending Him. Our desire not to offend God is more than simply a sense of duty; like piety, the fear of the Lord arises out of love.