Mistletoe has apparently been used as a decoration in houses for thousands of years and is also associated with many pagan rituals. 

　　The church forbade the use of mistletoe in any form, mindful of its idolatrous associations. As a substitute, it suggested holly. The sharply pointed leaves were to symbolize the thorns in Christ’s crown and the red berries drops of his blood. Holly became a nativity tradition. The Christian ban on mistletoe was in effect throughout the Middle Ages. Surprisingly, as late as the 20th century, there were churches in England that forbade the wearing of mistletoe sprigs and corsages during services