We actually do not know how many magi there were. Tradition speaks of three only because of the three gifts mentioned in Holy Scripture. The gifts are significant. Gold was a symbol of Christ’s royalty. Recall that they asked Herod about the birth of the new King. Frankincense is a symbol of prayer and of Christ being our High Priest. Myrrh was used to prepare Jesus’ body for burial so this gift foreshadowed His death to atone for the sins of the world.
One theory is that these men who came from the east were in the line of magi that date back to Daniel’s time during the Babylonian Captivity in the 6th century BC. In the Book of Daniel it is stated that the king placed Daniel over all the wise men of Babylon (2:48). If this theory is true then rather than being priests of Zoroastrianism who used astrology they would have been wise men who used the prophets and astronomy to guide them. Regardless, their act of worship was an open declaration that Jesus truly is Immanuel, God with us.