This evening marks the Jewish New Year, believed to be the birthday of the universe. 5781 years ago today, it is believed that God finished the creation of the world and called it good. Adam was created this day, and then God rested. It must be noted that this is not explicitly found in Scripture, but it is a belief that goes back as far as we know, and one that would make sense, being the beginning of the Year of Jubilee (Leviticus 25:10) which signifies the creation of the world by God. Additionally, Christ's ministry started in 26 A.D., a Year of Jubilee. He Himself mentions this in Luke 4:18-19 when He quotes Isaiah saying, "The Spirit of the Lord is on me, because He has anointed me to preach good news to the poor. He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed, to proclaim the year of the Lord's favor ("the year of the Lord's favor" was understood to be a reference to the Year of Jubilee). This holds incredible significance, as it means that Jesus chose this time to begin His ministry, on a likely anniversary of the world's creation and a Year of Jubilee.
For those wondering, the Year of Jubilee marks a time God decreed to remember the creation of the world and let the land rest for a year just as He rested on the seventh day. People were also commanded in the Old Testament to make their wrongs right at this time, to atone for things so the land could be jubilant. They would specifically do this during the Year of Jubilee, but even for normal new years like this one, Rosh Hashanah marks the beginning of a time of atonement on the Jewish calendar. If these commandments were carried out and atonement was made, then the land would be cleansed and experience great blessing with fruit coming from the vine in full (Leviticus 25: 19-21). Jesus was proclaiming to the world at the very outset of His ministry what His purpose was - to atone like no mere human being can, to atone for our very sins and cleanse the land of all sin.
Due to this aspect of atonement, Jewish people today do not celebrate this day like a holiday. They begin a cycle of atonement and repentance, as they believe they still must look forward to a future Messiah.
Rosh Hashanah also points to a time when God can once again look at His creation and declare it good. This redemptive plan was instigated by Him through Christ's atonement for our sins, its continuance heralded through Israel's regathering as a nation and re-devotion to God, and concluded by the Rapture and Final Judgement.
This regathering and re-devotion to God is associated with Rosh Hashanah by referencing its Biblical name, the Feast of Trumpets, when Isaiah says "and in that day a great trumpet shall be blown, and those who were lost in the land of Assyria and those who were driven out to the land of Egypt will come and worship the Lord on the holy mountain at Jerusalem." (Isaiah 27:13). The language of the Year of Jubilee is also used in that chapter, when Isaiah proclaims that "Therefore by this the guilt of Jacob will be atoned for, and this will be the full fruit of the removal of his sin." God further breaks down this process for us in Ezekiel 37, when He shows Ezekiel the valley of dry bones. First the scattered bones which appear fully dead and beyond repair are gathered up into a great multitude with flesh appearing upon them, and after this miraculous come back, life shall be breathed into them. God turns around and explains to Ezekiel that "these bones are the house of Israel. Behold, they shall say, 'Our bones are dried up, and our hope is lost, we are indeed cut off.' Therefore prophesy and say to them, Thus says the Lord GOD: Behold, I will open your graves and raise you from your graves, O my people. And I will bring you into the land of Israel. And you shall know that I am the LORD, when I open your graves, and raise you from your graves, O my people. And I will put my Spirit within you, and you shall live, and I will place you in your own land. Then you shall know that I am the LORD, I have spoken, and I will do it, declares the LORD." (Ezekiel 37: 11-14). And today, we see this prophesy being fulfilled in real time before our very eyes! God has indeed brought them back "into the land of Israel... plac[ing] you in your own land". And today, more Jewish people are being saved than ever before, as God begins to "put my Spirit within" them. As Isaiah said, so we see it happening today: "those who were lost in the land of Assyria and those who were driven out to the land of Egypt will come" (referenced above). Now we wait for the culmination of God's outpouring of the Spirit upon them as they "worship the Lord on the holy mountain at Jerusalem." (referenced above).
Finally, the Rapture and ultimate return of Jesus is connected to Rosh Hashanah, the Feast of Trumpets. Paul says that "Behold! I tell you a mystery. We shall not all sleep, but we shall all be changed, in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall all be changed." (1 Corinthians 25: 51-52). Jesus further clarifies this when He says, "Then will appear in Heaven the sign of the Son of Man, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of Heaven with power and great glory. And He will send out His angels with a loud trumpet call, and they will gather His elect from the four winds, from one end of Heaven to the other." (Matthew 24:17). This clarification further connects the final return of Christ with the regathering and repentance of Israel, as proclaimed in Zachariah 12:8 when God says, "And I will pour out on the house of David and the inhabitants of Jerusalem a spirit of grace and pleas for mercy [Ezekiel and dry bones], so that when they look on Me [Jesus coming on the clouds], on Him whom they have pierced, they shall mourn for Him." Ultimately, Jesus' final return will wash the land clean and "those of us who are alive, who are left, will be caught up together with them in the clouds to meet the Lord in the air, and so we will always be with the Lord." (1 Thessalonians 4:17).
God ordained seven feasts for Israel every year, and every single one of them carries enormous significance. Rosh Hashanah, the Feast of Trumpets, is no different. It commemorates the creation of the world when God said it was good, and looks ahead to a time when God can once again say that it is good - heralded by the regathering of Israel and culminating in their re-dedication to Him as He returns again to "judge the living and the dead" (2 Timothy 4:1).
So with that, happy new year!