In the Bible, the book of Revelation describes the heavenly city, the New Jerusalem, as having twelve gates, each made of a single pearl. These gates are not necessarily described as being there to keep people out in the way city gates are on Earth. Instead, they carry symbolic meanings:
Welcome and access — Gates represent entry into God's presence.
Security and peace — Ancient cities had gates for protection. In Revelation, however, the gates are said to never be shut, symbolizing complete safety and freedom from danger.
Judgment and belonging — Some traditions interpret the gates as representing that entry into heaven is through God's grace and according to God's will.
Connection to God's people — The twelve gates are associated with the twelve tribes of Israel, linking heaven to God's covenant with humanity.