Incense is used in many churches and temples of various religions including Christians (especially Catholics), Hindus and Buddhists, yet few know the spiritual symbolism of it.  Burning incense is a way of paying homage to God, but is also a symbol of purity.  The pleasant smelling smoke rising from the incense is symbolic of the soul or subtle body rising out of the physical body and flowing toward heaven.  It is often believed to repel evil spirits and demons so is often used in rituals such as exorcisms and cleansing haunted houses.  Incense can also represent a burnt offering to God or gods, but without killing any animals.  The burning smudge sticks of Native Americans is another form of incense.