Russian Traditions.

Russian Christianity gave rise to such great holidays like Easter, Christmas and the rite of Baptism. and Paganism gave rise to Pancake Day and Midsummer. (Since they are two different religions, separate them into two sentences).

Easter it’s (it's = it is) is a day of hearty treats.

After Lent on the table in this day and exhibited a variety of delicious dishes. Let's look at this sentence. There is not a subject, and two prepositions ("on the table" and "in this day") do not go together. If you are saying this day is after Lent and has delicious dishes, my correction would be: This holiday is after Lent and involves a variety of delicious dishes.

And among them, the first place belongs to (this phrase is used for competitions) The best of these dishes are the ritual meals. And, Above all, it's Easter Sunday, means Easter cakes and colored eggs.
The egg, which was painted in the traditional red color and its shades, became a mandatory attribute and a symbol of Easter in the XII century. A cake is always baked with dough, high and round. The top of the cake is decorated with a cross. It was believed that if the Passover bread was a success, the family all goes well will have a good year. When eating the cake, does it should not be cut lengthwise and crosswise.
And, of course, the Old Russian custom of these Easter days and echoed was to send gifts to the poor and needy, relatives and friends that are not the people in the almshouses, orphanages, hospitals and prisons. Do During this holiday, one should not abandon the poor and strangers. - It is popularly said that "from Easter to Ascension travels on earth, Christ and the apostles, experiencing the mercy and kindness of everyone."

Christmas is a holiday celebrating the birth of Jesus Christ, the savior of the world, with the advent of whom people have hope in the mercy, kindness, truth, and eternal life. The Orthodox Church celebrates Christmas according to the Julian calendar on January 7, unlike Western churches that celebrate it on December 25 in the Gregorian calendar.

Perhaps The most fun holiday in Russia, in my opinion, can be is called Shrove Tuesday. This festival is considered to be an echo of the pre-Christian times, when the Slavs were still pagan.
In the old days it was considered a carnival feast of All Souls. So burning carnival - it's her funeral, and pancakes - its Remembrance treat. (I'm sorry, I would correct this sentence, but I do not understand what you are trying to say.) But as time passed, and the Russian people, hungry for fun and relaxation, has turned into a changed this sad holiday daring into Shrove Tuesday. But there was a tradition of pancakes - round, yellow and hot as the sun, and added to her riding horse-drawn sleigh rides and ice slopes, fist fight, Teschin gatherings. (The end of this sentence also does not make sense.) Pancake rituals are very unusual and interesting, because they combine the completion of the period of the winter holiday rituals and the opening beginning of a new, spring season holidays and ceremonies that were to facilitate obtaining a rich harvest.
Pancake Day is celebrated a week before Lent, and every day of Shrovetide week was devoted to special rituals.

Good job. I like that you are trying to write with detail, but you are not at the level to write sentences this complex. The way you combined phrases does not always add up to a sentence. Keep your ideas simple and build from there.