Life of Constantine

But before this time another most virulent disorder had existed, and long afflicted the Church; I mean the difference respecting the salutary feast of Easter. For while one party asserted that the Jewish custom should be adhered to, the other affirmed that the exact recurrence of the period should be observed, without following the authority of those who were in error, and strangers to gospel grace.

Accordingly, the people being thus in every place divided in respect of this, and the sacred observances of religion confounded for a long period (insomuch that the diversity of judgment in regard to the time for celebrating one and the same feast caused the greatest disagreement between those who kept it, some afflicting themselves with fastings and austerities, while others devoted their time to festive relaxation), no one appeared who was capable of devising a remedy for the evil, because the controversy continued equally balanced between both parties. To God alone, the Almighty, was the healing of these differences an easy task; and Constantine appeared to be the only one on earth capable of being his minister for this good end. For as soon as he was made acquainted with the facts which I have described, and perceived that his letter to the Alexandrian Christians had failed to produce its due effect, he at once aroused the energies of his mind, and declared that he must prosecute to the utmost this war also against the secret adversary who was disturbing the peace of the Church.