What is Passover or Easter?
First of all, quit using the word "Easter". It is a pagan term. The correct term is Resurrection Sunday or Feast of First Fruits. The Holy Week or week of Easter can still be referred to as "Pesach", "Pascuas" or "Paques" as they do in France, Germany and Italy. It was correctly translated in the 1st century by those languages from the Aramaic and Hebrew word "Pesach".
What was really "The Last Supper" ?
The word "supper", "meal" etc. was never in the Bible. It was incorrectly translated in the King James translation. The correct term is "Seder". Seder has a much different meaning. Read Luke 22. Try to read a use a Greek or Hebrew recovery version if possible. You will understand why we should celebrate Pesach and Resurrection Sunday both.
When Passover (Pesach) hour had come Jesus and the 12 disciples sat down. He told them that with fervent desire I have wanted to share this SEDER with you before I suffer. I will not celebrate it again until it is given its full meaning in the kingdom of God. He then made the B'rakhah or blessing. Then having taken a cup, after He gave thanks he said to them you must share this amongst yourselves, For I say to you that from now on I wiil not drink the fruit of the vine again until the Kingdom of God comes.
 Then he took the matzoh (unleavened bread) and broke it and said This is my body which is given to you, Do this in remembrance of me. Then later he said, This cup is the New Covenant ratified by my blood which is being poured out for you, (all believers).
This Passover Seder he was celebrating is the highest holiday of all Jewish celebrations. It is the first feast commanded by God in Leviticus. It was celebrated by all the first Christians into the 4th century. Remember why Jesus left a safe place in Luke 18. His disciples begged him to stay where he was. With all the good he was doing there he was making great progress. But Jesus had to enter the dangerous Jerusalem where the corrupt chief priests and scribes wanted him dead. It was for His Father's highest holiday ordered to man. Pesach or 6oyoHoK.
If you study the Book of Acts you will find the first original Christians honored and celebrated all seven of the feasts God commanded. In 365 AD, the order of the emporer Constantine (originator of the Catholic church) outlawed all Jewish celebrations regardless if they were truly Christian or not. He renamed the Feast of First Fruits "Ishtar" to ease his troubles by honoring a pagan celebration of that name on that same Sunday.
LET'S GET STARTED WITH OUR STUDY!