The Advent season kicked off Sunday, with Pope Francis using the occasion to urge Catholics to be aware of Christ’s coming at all times.

"Season of #Advent, let us be shaken out of our torpor to recognize God’s present in daily situations,” the pope said in a tweet this week. “If we are unaware of his coming today, we will also be unprepared when He arrives at the end of time. Let us remain vigilant!”

The readings on Sunday also focused on the need to stay ready and prepare for the coming of the Lord.

Archbishop Thomas Wenski of the Archdiocese of Miami released a letter on the first Sunday of Advent titled "Advent: God acts to save us."

"Advent tells us to 'watch,' to be vigilant – because we will be the ones reviewed, our lives will be judged – and vigilant we must be since we do not know the day or the hour," he said in the letter. Wenski added that Advent is a sign that the end is just the beginning, in reference to Christ's life and salvation history.

“Advent” is derived from the Latin word meaning “coming,” a Crosswalk.com article said. Although Advent is typically thought of as the season of anticipating Christmas these days, it started as a time when early Christians would get ready for the baptisms of new Christians on the Epiphany. The Advent season also anticipated the Magi visiting the baby Jesus, Jesus’ baptism in the Jordan River, and Jesus’ first miracle at the wedding in Cana. Christians use the Advent season as a protracted period of fasting and prayer. Advent became linked to Christ’s birth in the Middle Ages.

The first Sunday of Advent celebrates hope, Crosswalk said. Catholics pray and reflect on hope in God’s plan for deliverance through Christ.

On the first Sunday of Advent, Catholics light the first purple candle on their Advent wreaths, an article in the Daily Press said. The candle is purple to symbolize preparation and repentance. The wreath symbolizes God’s eternal nature, as circles are without end. The pink candle, which is lit on the third Sunday of Advent, signifies that the waiting period for Christ's birth is almost over.

“Brothers and sisters: You know the time; it is the hour now for you to awake from sleep,” the second of the USCCB Daily Readings said, in which St. Paul writes to the Romans (Romans 13:11-14). “For our salvation is nearer now than when we first believed; the night is advanced, the day is at hand. Let us then throw off the works of darkness and put on the armor of light; let us conduct ourselves properly as in the day, not in orgies and drunkenness, not in promiscuity and lust, not in rivalry and jealousy. But put on the Lord Jesus Christ, and make no provision for the desires of the flesh.”