No. The Roman Empire's state religion was paganism until Theodosius the Great, AD 380 ... 55 years after Nicaea. Constantine was the ex officio head of the Roman state pagan religion.
This discussion is not a question of salvation.b'shem Yah'shuaIt is a valid question of worship of our coming King ,
who will sit on the throne of David in Jerusalem.
The Feast of Tabernacles (Feast of Sukkot or Feast of Booths) is an eight day
Judaeo - Christian festival (the Season of our Joy) that pictures the establishment
of the 1000 year messianic kingdom to be set up at the second coming of Yeshua
the Messiah (Christ). It is one of the three pilgrimage festivals God gave the children
of Israel in the Bible (Leviticus 23). It was during these festivals that the Israelites
would bring their offerings and firstlings to the Temple in Jerusalem and enjoy a feast!Sukkot (the Feast of Tabernacles ) is not a "Jewish festival", but rather a "Hebrew"
festival, for it was given to all the Israelite tribes, not just Judah. Today,
it would be observed by all of God's people since ". . . if ye be Christ's,
then you are Abraham's seed, and heirs according to the promise" (Gal 3:29).