Yes and no. But first, “a schism is the purposeful separation from the unity of the Church, the refusal to recognize the authority of the pope, and can result in excommunication.”

Now let’s start with the “yes” part. Since July of 1054, “the Roman Catholic Church of the West and the Orthodox Church of the East have [had] an ongoing rift: the Great Schism.”

So what are the issues at hand? First and foremost, the Eastern Orthodox Church’s creed professes that the Holy Spirit proceeds solely from the Father, and not also from the Son. In contrast, the Roman Catholic Church’s creed professes that the Holy Spirit proceeds from both the Father and the Son (filioque in Latin). [verify] Other differences between the two Churches include:

Celibacy is required of Roman Catholic priests, but not of Eastern Orthodox priests

The West believes in Purgatory ; the East does not

The West uses unleavened altar bread, whereas the East uses leavened

The Sign of the Cross is made differently in the two Churches

Importantly, the Eastern Orthodox Church does not recognize the authority of the pope

Now for the “no” part. “Before the Schism, there was one Catholic Church made up of Catholics living in [both] the eastern and [the] western parts of the Roman Empire. Following the Schism, those in the East called themselves Orthodox Christians and, in the West, Catholics. Eventually Catholics in the West became known as Roman or Latin Catholics. As centuries went by, 23 of the Orthodox Churches reunited with Rome and are called the Eastern Catholic Church. These Catholics accept the authority of the pope . . .”

Jesus established the one true Church, and anyone who knowingly and willfully separates himself from that, Jesus’s one true Church, does so at his own peril.