In the Church, an ordinance is a sacred, formal act performed by the authority of the priesthood. Some ordinances are essential to our exaltation. These ordinances are called saving ordinances. They include baptism, confirmation, ordination to the Melchizedek Priesthood (for men), the temple endowment, and the marriage sealing. With each of these ordinances, we enter into solemn covenants with the Lord.
Ordinances and covenants help us remember who we are. They remind us of our duty to God. The Lord has provided them to help us come unto Him and receive eternal life. When we honor them, He strengthens us.
You may receive many opportunities to participate in priesthood ordinances. Whenever you have such an opportunity, do all you can to prepare yourself, whether you are performing the ordinance or receiving it. You can prepare by praying, fasting, counseling with priesthood leaders, and studying the scriptures and the words of latter-day prophets. If you are a priesthood holder, you should always be spiritually prepared to perform an ordinance. Live a clean, worthy life, and strive to receive the constant companionship of the Holy Ghost.