Christians around the world observe Good Friday two days before Easter, but what is it, and why do they commemorate the holy day?

The holiday is apart of Holy Week, which leads up to Easter Sunday. Palm Sunday kicks off the the series of Christian holy days which commemorate the Crucifixion and celebrate the resurrection of Jesus Christ.

"Good Friday has been, for centuries now, the heart of the Christian message because it is through the death of Jesus Christ that Christians believe that we have been forgiven of our sins," Daniel Alvarez, an associate teaching professor of religious studies at Florida International University, told USA TODAY.

When is Good Friday?

Good Friday is always the Friday before Easter. It's the second-to-last day of Holy Week.

In 2024, Good Friday will fall on March 29.

What is Good Friday?

Good Friday is the day Christ was sacrificed on the cross. According to Britannica, it is a day for "sorrow, penance, and fasting."

"Good Friday is part of something else," Gabriel Radle, an assistant professor of theology at the University of Notre Dame, previously told USA TODAY. "It's its own thing, but it's also part of something bigger."

Are Good Friday and Passover related?

Alvarez says that Good Friday is directly related to the Jewish holiday, Passover.

Passover, or Pesach, is a major Jewish holiday that celebrates the Israelites’ exodus from Egypt.

"The whole Christian idea of atoning for sin, that Jesus is our atonement, is strictly derived from the Jewish Passover tradition," said Alvarez.

How is that possible?

According to the professor, Passover celebrates the day the "Angel of Death" passed over the homes of Israelites who were enslaved by the Egyptians. He said that the Bible states when the exodus happened, families were told to paint their doors with lamb's blood so that God would spare the lives of their firstborn sons.

Alvarez says this is why Christians call Jesus the "lamb of God." He adds that the symbolism of the "blood of the lamb" ties the two stories together and is why Christians believe God sacrificed his firstborn son. Because, through his blood, humanity is protected from the "wrath of a righteous God that cannot tolerate sin."

He adds that the stories of the exodus and the Crucifixion not only further tie the stories together but also emphasize just how powerful the sacrifice of the firstborn and the shedding of blood are in religion.

"Jesus is the firstborn, so the whole idea of the death of the firstborn is crucial," said Alvarez.

He adds that the sacrifice of the firstborn, specifically a firstborn son, comes from an ancient and "primitive" idea that the sacrifice unleashes "tremendous power that is able to fend off any kind of force, including the wrath of God."

Why Is Good Friday so somber?

Alavarez says people might think this holiday is more depressing or sad than others because of how Catholics commemorate the Crucifixion.

"I think [it's] to a level that some people might think is morbid," said Alvarez.

He said Catholics not only meditate on Jesus' death, but primarily focus on the suffering he faced in the events that led up to his Crucifixion. That's what makes it such a mournful day for people.

But, the professor says that Jesus' suffering in crucial to Christianity as a whole.

"The suffering of Christ is central to the four Gospels," said Alvarez. "Everything else is incidental."

According to the professor, statues that use blood to emphasize the way Jesus and Catholic saints suffered is very common in Spanish and Hispanic Countries, but not as prevalent in American churches.

Do you fast on Good Friday?

Father Dustin Dought, the executive director of the Secretariat of Divine Worship of the United States Conference of Catholic Bishops, previously told USA TODAY that Good Friday and Ash Wednesday are the two days in the year that Roman Catholics are obliged to fast.

"This practice is a way of emptying ourselves so that we can be filled with God," said Dought.

What do you eat on Good Friday?

Many Catholics do not eat meat on any Friday during Lent. Anything with flesh is off-limits. Dought says this practice is to honor the way Jesus sacrificed his flesh on Good Friday.

Meat that is off limits includes:

• Poultry
• Pork
• Beef

Instead, many Catholics will eat fish. According to the Marine Stewardship Council, this is allowed because fish is considered to be a different type of flesh.

Contributing: Jordan Mendoza; USA TODAY