Astrology at one time was looked upon with great seriousness by the educated classes. For many centuries people believed that the earth was the center of the universe, and this mistaken cosmology led to the conviction that the personality and character of people could be influenced by the position of the heavenly spheres at their time of birth.
Since the introduction of modern astronomy, it became impossible for any serious-minded scientist to accept the original principles of astrology. Besides the fact that the heavenly bodies are at a much greater distance than our ancestors believed them to be, their positions in the sky have drastically changed with the passage of time.
After the scientific discoveries of the Enlightenment made the original basis for astrology untenable, there have been numerous attempts by occultists to maintain confidence in it by mystical and occult means.
Though there is no genuinely scientific basis for astrology, millions of people resort to daily horoscopes for guidance in their lives. If nothing else, this behavior shows how deeply religious people are, and how strongly they long for a basis for hope and faith. It may not harm someone to read horoscopes, but anyone taking them seriously will be endangered.
At the very least, astrology is a crutch to avoid the effort of seeking out an informed basis for our decisions. At its worse, it becomes compulsive, a false god gripping us with demonic power. This is probably why the Old Testament warns against it (Isaiah 47:13).
(For more information about the occult, see the Discovery Series booklet What’s The Appeal Of The New Age Movement?)