Easter is the oldest Christian festival. Commemorates the resurrection of Jesus Christ.
Second sentence, Gamer, lacks subject, s/b "It commemorates…" Or you might say, "…festival commemorating…"
Easter is celebrated on different days. In 2014, Easter will be celebrated April 20.
Grammar is okay but meaning unclear. Maybe s/b "Easter has been celebrated on different dates. In 2014 it will be celebrated April 20."
…or just "In 2014 Easter will be celebrated April 20," clearly implying formerly other dates
Worship during Easter for Catholics and Orthodox is different, but the same folk tradition of celebrating.
Meaning not clear since it doesn't reveal how the worship is different nor what folk tradition comprises the apparent similarity. Now I'm only guessing, but "Easter worship for Catholic and Orthodox differ markedly by interpretation of the Bible but in folk tradition share the claim of apostolic succession"
In Easter color eggs and cook cake.
Sorry Gamer and no offense but this one makes no sense whatever. Wondering if it means "At Eastertime we color eggs and bake hot cross buns"