The aroma of a favorite dish cooking can fill a house and cause an immediate emotional reaction in anyone who enters. Just the scent brings pleasure and leaves us wanting to taste the subject of that scent. Your sense of smell is powerful and draws you to something if it is pleasant or repels you if it is unpleasant. If it is a good smell, you want more of it; if it is a bad smell, you want nothing to do with it. And if the scent is really good, it can be recorded in your brain and, at a later date, can arouse pleasant memories of your past. The sense of smell is an incredible gift.
If you study the sacrificial system of God's people in the Old Testament you will notice that the Bible describes a burning sacrifice as creating "a soothing aroma to the Lord". Additionally, as a part of worship, the people would burn incense before the Lord and the aroma pleased Him. God has a sense of smell too and that sense is important to him. David, a man God described as "after my own heart", understood this when he proclaimed Psalm 141:2, "May my prayer be counted as incense before you...". Thinking about our prayer as being a soothing aroma to God should cause us to think differently about our prayers.
The stakes are raised a little more in 2 Corinthians 2:15-16 when it said, "For we are a fragrance of Christ to God among those who are being saved and among those who are perishing; to the one an aroma from death to death, to the other an aroma from life to life." Now, our lives in Christ are a fragrance to God. This should have a powerful impact on the life of a believer. When God considers His children who walk in spirit with Him, it is like the sweet smell of a favorite perfume or of pleasant incense to Him. Also, that aroma is smelled by others and brings pleasure to those who are saved. However, to those who are without Christ, it is the unpleasant scent of reminder of what is missing in their lives. But regardless of whether or not you are aware, your life is a fragrance. So live your life so that it will be a sweet fragrance - both to God and to those with whom you come into contact.