Patriarch Alexei II of Moscow(right) and Metropolitan Laurus of the Russian Church Outside of Russia embrace

When Blessed Polycarp paid a visit to Rome in Anicetus’ time, though they had minor differences [on the day on which Easter should be celebrated], they at once made peace, having no desire to quarrel on this point.

Anicetus could not persuade Polycarp not [to break the Lentern fast on the same day as the Jewish Passover], since he had always done so with John the disciple of our Lord and the other Apostles with whom he had been familiar. Nor did Polycarp persuade Anicetus to keep [the Jewish Passover]: Anicetus said he must stick to [celebrating Easter on the Sunday, the day of the resurrection], the practice of the presbyters before him. Though the position was such, they remained in communion with each other, and in church Anicetus made way for Polycarp to celebrate the Eucharist [on the 14 Nisan] – out of respect, obviously.

They parted company in peace, and the whole Church was at peace, both those who kept the day and those who did not.

-Letter from Irenaeus to Pope Victor (2nd Century AD)

I would just like to post the above in response to my previous post on some Chinese Christians celebrating Jewish festivals. I doubt they have direct Apostolic sucession back to the Apostle John, but nevertheless eireine if they wish to do this. The Christians in China, in terms of practicing their faith, have far worse problems.