This got me thinking. I'm so involved in all this churchy stuff that I lose perspective on what is common knowledge and what isn't. I might be tempted to respond, "Duh! It's Holy Thursday!" much the same way I'd like to respond, "It's Ash Wednesday, you moron," whenever someone points out that I have something on my forehead.
How soon I forget! I wasn't always such a devout Christian. I was only confirmed Catholic some 11 years ago. And I didn't fully understand a lot of things about Catholicism in particular or Christianity in general. I suppose there's still a lot I don't fully grasp. A lot of active Christians, Catholic and non-Catholic alike, seem not to understand or appreciate a lot of these things as well. For instance, I ran into a regular parishioner on the way to Mass tonight and was surprised to learn he didn't realize there was a special Mass. The point is I shouldn't assume people will know about important Christian holidays other than Christmas and Easter, and I should, therefore, do a better job of understanding their perspectives. I attempted to answer the commenter's question in that spirit, but I felt I should expand on my answer and post it for a wider audience.
Before I do so, I want to clarify something. I am a devout Catholic. However, what I'm about to post isn't specific to Catholicism. It's what is practiced by the major Christian denominations (Catholic, Anglican/Episcopalian, Lutheran, Methodist, Presbyterian, Baptist). I regularly attended a Methodist church for over a year when I dated emilykb and an American Baptist church for two years and taught at a Presbyterian Vacation Bible School, all before I returned to Catholicism. I just wanted to dispel any idea that this post is pushing a Catholic-centric line of thought.
So, what is Holy (or Maundy) Thursday?
Holy Thursday, the Feast of the Lord's Supper, is the first feast day of the Easter Triduum, which also includes Good Friday and Easter Sunday (observance of which begins with a vigil mass/service on Saturday night). Collectively, these three celebrations mark the most important dates in the Christian calendar. I'm going to assume you know that Good Friday commemorates the Christ's crucifixion, death, and descent into hell and Easter Sunday, His resurrection.
On Holy Thursday we celebrate three things. First, we remember the Passover. Christians do not regard their religion as a rejection or derivative but rather a culmination of Judaism. We believe the Lord made good on his Covenant and gave us His only son to be the promised Messiah, bringing a new covenant. Yet, as Exodus 12:14 tells us, "This day shall be for you a memorial day, and you shall keep it as a feast to the Lord; throughout your generations you shall observe it as an ordinance for ever." The Christian heritage is the Hebrew heritage, and we have not forgotten. I think it is extremely symbolic that the Christ's last supper with his apostles was a Passover seder.
Second, we celebrate the institution of the Mass and the Eucharist. I speculate that we don't have seders because we celebrate a daily seder, Mass, with our Church family. The main elements of the high church Mass are drawn from the last supper: the reading of Scripture, the blessings, the communal sharing of unleavened bread and wine. The meaning of the bread and wine differs amongst denominations, with Catholics believing it to be transsubstantiated into the body and blood of Christ and others seeing it as an important symbolic gesture, yet this shared meal is common to them.
The third thing we celebrate is the washing of the feet. In washing the apostles' feet, Christ gave us a very powerful testament to his message of love: "For I have given you an example, that you also should do as I have done to you." (John 13:15) It was a small gesture, but one that underscores what He preached throughout His mission: Christian love is not about self-importance or self-aggrandizement but about humility, self-sacrifice, and service to others.
This is why Holy Thursday is so significant to Christians. Please accept this post in the spirit it is intended, which is to promote understanding.