The law of celibacy has no doctrinal bearing in the Catholic Church--it is a mere disciplinary law. Even today, there are married Catholic priests in the United States. Each is a former Episcopalian priest who joined the Catholic Church. There are Uniate Churches, churches in union with Rome, e.g., the Greek Byzantine Church, who have a married clergy.
Priestly celibacy became law in the Roman Church in the 6th century.
John 6.66=Mark of the Beast?
Yes.