Question: "Why didn't Jesus return during the blood-red moon of 2015?"
Answer: A popular teaching in the past couple years was that a series of blood-red moons in 2014 and 2015 would be a portent of Jesus’ second coming and a fulfillment of biblical prophecy. A lunar eclipse is sometimes referred to as a “blood moon” or “blood-red moon” because of the red or orange color of the moon during that phenomenon. There were four lunar eclipses in 2014 and 2015. Some teachers of prophecy predicted that this tetrad of blood moons would fulfill end-times prophecies in Joel and Revelation.
What interested prophecy teachers was not just the number of lunar eclipses in those two years but the timing of the eclipses. In both 2014 and 2015, a full lunar eclipse occurred on the first day of Passover and the first day of Sukkot (the Feast of Tabernacles). In addition to the two lunar eclipses of 2015, two solar eclipses also occurred. Similar lunar eclipses in back-to-back years have happened seven times since the time of Christ. Some of those have occurred in years of significance for the Jewish people, such as 1948 (when Israel was granted statehood) and 1967 (when the Six-Day War was fought).
References to a moon like “blood” are found in two passages of the Bible. Joel 2:30–31 says, “I will show wonders in the heavens and on the earth, blood and fire and billows of smoke. The sun will be turned to darkness and the moon to blood before the coming of the great and dreadful day of the Lord.” In Revelation 6:12, John describes one of the seal judgments of the Tribulation: “I watched as he opened the sixth seal. There was a great earthquake. The sun turned black like sackcloth made of goat hair, the whole moon turned blood red, and the stars in the sky fell to earth, as figs drop from a fig tree when shaken by a strong wind. The heavens receded like a scroll being rolled up, and every mountain and island was removed from its place.” Other passages refer to the moon being “darkened” (Matthew 24:29; Joel 2:10).
A tetrad of lunar eclipses—and the timing of those eclipses in the Jewish calendar—is fairly unusual, but not unprecedented. So the fact of the eclipses, while interesting, was no proof that Jesus would return by 2015. Furthermore, John’s and Joel’s descriptions of the signs of the Day of the Lord could refer to solar and lunar eclipses, but there are other possible explanations for those phenomena, such as changes in the atmosphere (mentioned in Revelation 6:12).
The blood-red moon theory was always just that—a theory, regardless of the adamancy of some teachers. Even as a theory, it came close to doing what the Bible warns against: setting dates for the coming of the Lord. “About that day or hour no one knows” (Mark 13:32). Why didn’t Jesus return during the blood-red moon of 2015? Because it was not yet time for Him to return.