“And as it is appointed for men to die once, but after this the judgment, so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation” (Hebrews 9:27-28).
Though it is commonly heard, “Jesus’ second coming” in reference to His final coming is really not Biblically accurate.
“The day of the Lord” is a phrase used in both the Old and New Testaments. It is a significant and sobering term which was usually written to warn of a coming day of divine judgment upon a person or nation. In Joel’s day, for example, a locust plague in the land of Palestine was termed “the day of the Lord” (1:15, 2:1). It was a day of darkness and gloominess (2:2), great and very terrific (2:11). God’s people needed to repent and turn to Him with fasting, weeping, and mourning (2:12). In addition to Joel, the prophets Isaiah, Jeremiah, Ezekiel, Amos, Obadiah, Zephaniah, Zechariah, and Malachi all use this phrase to depict God’s coming in judgment.
In the New Testament, the day of the Lord as prophesied in Joel 2:28-32 was fulfilled on Pentecost in Acts 2 when Jesus—who God made both Lord and Christ (v. 36)—baptized His apostles with the Holy Spirit. This baptism would subsequently result in further divine revelation (v. 18), miraculous powers to confirm the message of the apostles (v 19), the destruction of Jerusalem (v. 20), and the gloriously good news that whoever calls upon the name of the Lord/obeys the gospel shall be saved (v. 21).
When the divine judgment predicted by Jesus prior to His death and foreshadowed by the Holy Spirit’s baptism was executed upon the Jewish nation via the Roman army, Jesus came to carry out that sentence (Matthew 24:29-31).
In light of these two comings of Jesus which occurred in the first century, it is not Biblically accurate to describe the still future day of the Lord in which He will come as a thief in the night (1 Thessalonians 5:2) and the physical universe will be dissolved with great noise and intense heat (2 Peter 3:10-11) as His second coming; rather, it will be His final coming.