The Episcopal Church relies on three main sources for belief:
Scripture: The Bible (The Old and New Testaments and the Apocrypha) is the primary source of faith and belief. It is the record of humankind’s relationship with God in history and is the record of the ultimate revelation of Jesus Christ as the Son of God and savior of the world.
Reason: The Episcopal Church has long emphasized the importance of faithful and thoughtful interpretation. Rather than controlling the beliefs of its members, The Episcopal Church stresses the importance of individual and communal exploration and discernment of God’s work in our lives. Through the guidance of the Holy Spirit, we are called to make faithful, ethical, and moral decisions that impact our faith and practice.
Tradition: The Episcopal Church is rich with tradition. By interacting with prayer, worship, and music that have been utilized in the worship of God for many years, we are able to learn and be enriched by the traditions of our forebears.
In baptism, Episcopalians affirm their belief in God: Father, Son, and Holy Spirit (the Holy Trinity), the salvation of humankind through the suffering, death, and resurrection of Jesus Christ, and the forgiveness of sins. Episcopalians also promise to respect the dignity of all people, to strive for justice and peace, and to proclaim by word and example the Good News of God in Christ.
If you would like a more in-depth description of our beliefs, here is an excellent resource: http://www.episcopalchurch.org/page/baptismal-covenant