The Egyptian gods Osiris the Lord and Anubis the Purifier play roles very similar to those of the later Jesus Christ and John the Baptist. Indeed, an archetypical seasonal transition is described in the New Testament, with Jesus "the Sun of Righteousness" (Mal 4:2) representing the winter-to-summer season, while John "the Forerunner" symbolizes the six-month cycle from the summer solstice to the winter, explaining the mysterious passage at John 3:30: "He must increase, but I must decrease."
In this same regard, John "was not the light, but came to bear witness to the light." (Jn 1:8)
Although the Bible does not specify the dates of John and Jesus's birthdays, their conceptions are stated biblically to have been six months apart (Luke 1:36), and the Baptist's birthday began to be celebrated at the summer solstice (June 24th) in early Christian times.
Excerpted from The 2015 Astrotheology Calendar.