The Catholic Church was founded by Christ. The Episcopal Church traces it’s origins to King Henry VIII.
St. Peter was the first leader of the Catholic Church and throughout the centuries, his Successors have continued to lead the Church. The Episcopal Church has no real leader.
The Catholic Church has a unified set of beliefs. The Episcopal Church does not; members are free to decide for themselves.
Although they develop as a result of increased understanding, Catholic doctrine does not change. The Catholic Church never changes it’s beliefs or faith. When public opinion changes, so do the beliefs of the Episcopal Church.
The Catholic Church is One, Holy, Universal, and Apostolic:
We are One because we are united to the Pope. We also profess one unified faith throughout the world.
The Church is Holy because it is guided by the Holy Spirit.
The Church is Catholic/Universal because it is worldwide. It is the largest Christian faith in existence. The Church is also the oldest institution in the world.
The Church is Apostolic because all Bishops trace their lineage directly to the Apostles. The Catholic Church also teaches the undiluted faith of the Apostles.
The Episcopal Church is not united in obedience under one leader. The Episcopal Church does not profess one, unified faith throughout the world.
The Episcopal Church is not guided by the Holy Spirit in matters of faith and morals. The Holy Spirit would never guide the Church to consecrate homosexuals to the Bishopric, or endorse the female priesthood. God would never contradict himself.
The Episcopal Church is part of the Anglican Communion. The Anglican Communion is not a Church, but a group of Churches united by tradition and not by faith. For this reason, the Episcopal Church is not universal.
The Episcopal Church no longer possesses Apostolic Succession. Apostolic Succession was ruined because the ritual of Holy Orders was changed. Some Episcopal Bishops may possess Apostolic Succession, but the majority do not.
In conclusion, the Catholic Church is the Biblical Church and the Episcopal Church is the invention of a King who wanted absolute control.