Christ's birth fulfilled specific Old Testament prophecies, and these fulfillments mark Him as the Messiah. The angel convinced Mary by quoting Scripture to her, particularly Isaiah 7:14, that a virgin would conceive and bear a son called Immanuel, "God with us," and Isaiah 9:6-7, that a Child would be born who would bear the government on His shoulder, sit on David's throne, and rule over His kingdom with justice, with no end to His reign. Religious Jews expected Messiah soon and knew these prophecies had to come to pass for Him to be born. Gabriel gave the name Jesus, meaning Savior, which is not so different from Immanuel, since only God can save. Mary was of David's line, and Joseph, her husband, was of the house of David, so Jesus would physically claim David's throne through him. His conception by the Holy Spirit, the power of the Highest, was God's miracle, not human doing. Matthew adds that all this was done to fulfill what the Lord spoke through the prophet, and the angel told Joseph that Jesus would save His people from their sins. Elizabeth's miraculous pregnancy and the leaping of the unborn John confirmed the message to Mary. The assurance that no word from God is powerless echoes Isaiah 55:11: what God has spoken, He accomplishes.

God has provided messianic revelations through signs over centuries to inform and encourage His people that He has not forgotten His promise to supply the Savior and Redeemer needed to free humanity from bondage to sin and death. These signs began with the judgment in Genesis 3, where little information was given except that Eve, the only female at the time, would bear the Promised Seed. Though her first son was not the Messiah, the lineage of the Promised Seed can be traced from Seth through Noah, Abraham, Jacob, Judah, King David, and finally to Joseph and Mary when He was born in Bethlehem, Judea. Over 4,000 years, God added reminders and precise descriptions to help the Israelites identify the Messiah's appearance when He was sent. God kept His word by sending the Messiah, who performed His responsibilities admirably. In Genesis 12:1-3, God promised Abram that the Promised Seed would come from his line. Further details were given through Moses, emphasizing the Messiah as a prophet like Moses but far greater. King David's family within the tribe of Judah was sanctified, and God's promise to David included the eternal establishment of his throne through the Messiah. Isaiah 9:6-7 provided additional definition to the responsibilities the Promised Seed would hold, and Bethlehem Ephrathah was identified as the family's home base where He was indeed born. In the New Testament, the four gospel accounts explicitly identify Jesus of Nazareth as the promised Messiah. God did not hide His arrival, using angels to reveal the virgin birth to Joseph and Mary, a light from the sky to pinpoint His birth location, and announcements to shepherds who spread the news in Bethlehem. An angel proclaimed Him as the long-awaited Savior. Matthew and Luke provide genealogies aligning with Old Testament prophecies, and specific signs, such as His swaddling cloths and Simeon's prophecy that He would be a sign spoken against, distinguished Him. Additional signs included the wise men's journey, the flight to Egypt, and His intelligence on biblical subjects at age twelve, where He referred to God as His Father. John, Jesus' cousin, also served as a sign by preparing the way for Christ's ministry, clearly announcing the arrival of the long-awaited Promised Seed, Messiah, Redeemer, Savior, and Creator. When Jesus began His public works, He stood out to true believers. In His hometown, He gave clear signs by keeping the Sabbath and declaring the fulfillment of Isaiah 61:1-3, claiming divine anointing and the mission to set people free from bondage, further identifying Himself as the Messiah.

The only sign Jesus gave to prove He was the Messiah was the length of time He would lie in the grave: "as Jonas was three days and three nights in the whale's belly, so shall the Son of man be three days and three nights in the heart of the earth" (Matthew 12:39-40). When the Pharisees demanded supernatural proof, He offered no other evidence, and the sign was not the fact of the resurrection itself but the duration of His entombment. Jesus staked His claim to be Savior on remaining exactly three days and three nights, which Scripture defines as 72 hours, twelve-hour days and twelve-hour nights. Jonah's time in the fish is the pattern, and Genesis 1 shows that each day includes a night and a day. If He failed in this sign, He must be rejected as an impostor. Other texts, such as "after three days" and "in three days," confirm the same full length of time. A Friday sunset to Sunday sunrise burial covers only about 36 hours and cannot fulfill it. Because He was buried in the late afternoon, the resurrection had to come at the same hour three days later. The angel's words, "He is risen, as he said," testify that Jesus fulfilled the sign precisely, which proves He is the Christ.