The article from Faithlife Study Bible that explains the story with background information that is told in Matt 16:13–20; also Mark 8:27–29

Jesus’ Declaration at Caesarea Philippi The gospel accounts present Caesarea Philippi as the site of a defining confession in the story of Jesus’ life. There, after Jesus asked the disciples who they believed Him to be, Peter confessed Him to be “the Christ, the Son of the living God” (Matt 16:16). In Matthew’s Gospel, the account continues with a powerful declaration by Jesus about the Church and its mission (Matt 16:13–20; compare Mark 8:27–29)—a statement that continues to inspire interpretation about the nature of the Church and its role in God’s redemption of creation (see note on Matt 16:18, see also note on Matt 16:19). The Bible only records Jesus traveling to Caesarea Philippi on this one occasion. Why would He intentionally take a 14-hour walk (a 30-mile journey) away from the region of the Sea of Galilee where most of His ministry took place? Caesarea Philippi is located in the northern part of Israel in a plain in the upper Jordan Valley along the southwestern slopes of Mount Hermon. This ancient city was built on and against a majestic rock formation with lush vegetation. It served as the water source for the Huela Marshes that gave birth to the Jordan River. Augustus gave Caesarea Philippi to Herod the Great in 20 bc. Formerly called Panion (and later Paneas), the city was renamed Caesarea Philippi by Herod’s son, Philipp II, in 3 bc in honor of Caesar Augustus. The naming of this city as Caesarea Philippi differentiated it from Caesarea Maritima, which was located on the coast of the Mediterranean Sea. Herod also made the city the administrative capital of the region. The city was formerly called Paneas because it housed a cave and spring dedicated to the Greek god Pan. A temple to Pan was built in the midst of the city at the mouth of this cave, where people would make sacrifices to him. According to a narrative at his temple, Pan was one of the few gods who could cross into Hades and return to earth. As result, this site was recognized as the gate of Hades in the disciples’ day. Christ’s declaration about the Church was given powerful significance because it was uttered here. Given this, Peter confessed Jesus to be “the Christ, the Son of the living God” at the temple of a false god (Matt 16:16). Jesus followed by declaring that “on this rock” He would build His Church (Matt 16:18). He continued by professing that the gates of Hades (on which He may have literally stood) will not prevail against the Church (Matt 16:18). From that point on, He began to tell them of His impending sacrificial death that would make all of this possible (e.g., Matt 16:21). Jesus fulfilled this declaration by dying on the cross and rising on the third day. Today, His Church is powerful and glorious while the temples of the Greek and Roman gods lie in ruins. Chuck Booher

John D. Barry et al., Faithlife Study Bible (Bellingham, WA: Lexham Press, 2012, 2016).

I think you will like Logos! Get $100 off a Logos 10 base package (first-time base package purchasers only) from my link: https://logos.refr.cc/ricklivermore?t=em Furnished by Rick Livermore Webmaster220 San Juan Capistrano California –  https://rick-livermore-on-blogger.blogspot.com/