ChristianAnswers.Net WebBible Encyclopedia
from the Greek theophaneia [theo- (God) + -phaneia (to show oneself, appear)]
the visible appearance of god to a human being
The Creator appeared to Adam and Eve in visible form in the Garden of Eden (Genesis 3:8). “This is not a crude anthropomorphism, but an actual theophany. The ‘Word of God,’ Christ in His preincarnate state, regularly appeared in the garden for fellowship and communication with His people. How long this period of fellowship had endured is not stated, but it was long enough for the Satanic rebellion in heaven and expulsion to Earth. Since it was not long enough for Eve to conceive children, however, and since she and Adam had been instructed by God to do so, it was probably not more than a few days or weeks” (Dr. Henry M. Morris, The Defender's Study Bible).
The Son of God took on a visible form at various times in the Old Testament, appearing to:
God has only shown himself to man in the form of the Son, Jesus Christ, both incarnate and preincarnate (Matthew 11:27). However, God has revealed his power and invisible attributes in all that He has created (Romans 1:20; Colossians 1:16).
The Orthodox Church celebrates a Feast of Theophany (January 6). “It commemorates the baptism of the Lord Jesus Christ, and much more, as its name implies. …the Holy Trinity was made manifest after His baptism (when He came out of the water).”