Why is "Pesach" (Passover) celebrated?

Passover is one of Yahweh's feast as described in Exodus 13:1-8

1And יהוה spoke to Mosheh, saying, 2“Set apart to Me all the first-born, the one opening the womb among the children of Yisra’ĕl, among man and among beast, it is Mine.” 3And Mosheh said to the people, “Remember this day in which you went out of Mitsrayim, out of the house of slavery. For by strength of hand יהוה brought you out of this place, and whatever is leavened shall not be eaten. 4“Today you are going out, in the month Aḇiḇ.

5“And it shall be, when יהוה brings you into the land of the Kena‛anites, and the Ḥittites, and the Amorites, and the Ḥiwwites, and the Yeḇusites, which He swore to your fathers to give you, a land flowing with milk and honey, that you shall keep this service in this month. 6“Seven days you eat unleavened bread, and on the seventh day is a festival to יהוה.

7“Unleavened bread is to be eaten the seven days, and whatever is leavened is not to be seen with you, and leaven is not to be seen with you within all your border. 8“And you shall inform your son in that day, saying, ‘It is because of what יהוה did for me when I came up from Mitsrayim.’

Passover is one of the most important religious festivals in the Jewish calendar. Jews celebrate the Feast of Passover (Pesach in Hebrew) to commemorate the liberation of the Children of Israel who were led out of Egypt by Mosheh. Today we celebrate as a reminder of his Merci and love for all.