Polycarp, a bishop of Smyrna was a man that knew the apostles personally and received the episcopate from them. This Polycarp affirmed what he had received from the apostles that the Passover should be kept in accordance with the ancient tradition of the Jews. We know this from Irenaeus (through Eusebius).
Polycarp journeyed to Rome in his old age and met with Anicetus to convince him to keep the ancient tradition as it was handed down from the apostles. Anicetus chose rather to keep the tradition of his fathers in Rome, which was to observe the Passover on the Sunday immediately following the Jewish observance. There is no record of Anicetus saying he believed his tradition to be apostolic. Nevertheless, Anicetus and Polycarp agreed to disagree. The universal church now had a firm point of separation, but kept mutual respect in brotherly love.
About 30 or 40 years later there was an attempt to unify the church regarding the Passover feast. Bishops gathered in synods all over the known world to discuss and ultimately draw up an ecclesiastical decree to keep the feast on the day of the Lord’s resurrection. The bishops in the west and Palestine, including Alexandria, all agreed to the decree because that was the tradition they held. But the churches of Asia Minor remained steadfast in their opposition holding to the ancient tradition and provided evidence of apostolic authenticity for doing so.
For their opposition, the bishop of Rome (Victor) attempted to excommunicate all the churches of Asia Minor and referred to them as heretics. He actually wrote letters to the churches in Asia informing them of this. But Irenaeus backed the other bishops in the west, rebuked Victor for his actions. Irenaeus reminded Victor that their ancestors did not agree on the tradition yet they lived in peace with one another.
When the church emerged out of the great persecution under Diocletian, Galerius, and Maximinus, and met in Nicea upon the Emperor Constantine’s request, it was a dissimilar entity. This time the majority ruled and the minority was forced to comply. Regard for what had clearly been handed down from apostolic origin was abandoned. And a new, never heard of before precedence was established. Constantine, whose purpose in calling the council was to establish strict unity, wrote a letter to the churches upon the council’s conclusion wherein he declared, “Receive, then, with all willingness this truly Divine injunction, and regard it as in truth the gift of God. For whatever is determined in the holy assemblies of the bishops is to be regarded as indicative of the Divine will.” (Life of Constantine 3:20)
This new precedence was carried forward into subsequent councils that regarded Nicea as the standard for all church councils. Some 40 years later Laodicea threatened anathema to anyone found to be a Judaizer by resting on Saturday rather than Sunday. By implication, it was against canon law, and thereby punishable by excommunication to observe the Passover (Easter) on any day but Sunday.
It is clear from history that Constantine and the council of Nicea overruled the will of God, which is peace, love, and liberty in Christ Jesus. The bishops of the Council of Nicea determined that they themselves would decide the will of God and that Christians aught to regard them as God’s holy mouthpiece. The church did not only reject the apostolic tradition proclaimed by Polycarp, but observing it became a sin against God…or so they teach.