We may not know what tomorrow holds but we know who holds tomorrow. The purpose of a horoscope is to gain insight into a person's character and foretell the future. The basic belief of astrology is that planets and stars exert an influence upon our lives. Those with special knowledge, "astrologers", can predict events in a person's life.
It is distressing that most major newspapers have a horoscope column, and even more distressing that many Christians read their horoscopes. I've been guilty of this. Seriously guilty of it. But God has done such a profound change in my life, the thought of bringing the occult into my life anymore, and yes, horoscopes are of the occult, brings cold chills to the back of my neck. When you dabble with the occult, you open doorways by which demons can creep into your life.
The Bible expressly forbids divination, sorcery, and hidden arts (Deuteronomy 18:10-14). God's people are to heed God only (Deuteronomy 18:15). Any other source of guidance, information, or revelation is to be rejected outright. (See also Acts 16:16-18.) The Bible points to Jesus Christ as the only proper focus of faith (Acts 4:12; Hebrews 12:2). Our trust is in God alone, and we know that He will direct our paths (Proverbs 3:5-6).
Faith in anything besides God is misplaced.
Astrology, then, opposes biblical teaching in at least two ways: it advocates faith in something other than God, and it is a form of divination. We cannot determine God's will for our lives through horoscopes. As Christians, we are to read the Bible and pray to God in order to gain wisdom and guidance. Consulting a horoscope is a violation of God's means of communicating with His children. As a Christian, I strongly believe that horoscopes should be rejected by Christians.