Why do we use "smoke" in Church?

One of the most frequently asked questions from my second graders is why do we use incense or "smoke" in Church? They complain it smells and makes them cough. In fact I often notice many people begin to cough as soon as they see the thurible and it hasn't even been lit. The explanation is so magnificent and represents such majesty in giving glory and honor to God, I get very carried away when given the opportunity to answer this question. I hope this sheds some light on the subject. The incense reminds us of the "shekinah", the Glory Cloud of God coming down in the Temple of Jerusalem to accept the sacrifices made to God in the Temple. I remind the children of the visible signs of an invisible reality that we have learned with the sacraments. In using the incense, a visible sign, we are reminded of the sacrificial offering of Christ on the altar and God accepting the sacrifice. When the sanctuary fills with smoke from the incense it reminds us of God coming down and accepting our offering. We know that God in Heaven has come down to sit on the Glory Seat. What an incredible moment at that time of the Mass. No wonder we are bowed down in awe and prayerful worship. Aleluia!