Question: "Why would the aroma of a sacrifice be important to God?"
Answer: On sixteen different occasions in the book of Leviticus, an “aroma” is mentioned as something pleasing to the Lord. Specifically, the aroma of a sacrifice is important to God.
The importance of a sacrifice’s aroma is not the smell but what the smell represents—the substitutionary atonement for sin. The very first mention of God smelling the aroma of a burnt offering is found in Genesis 8:21. Noah offered a burnt offering of clean animals and birds after leaving the ark. We are told it was a “pleasing” aroma to God. The idea is that Noah’s sacrifice was a propitiation, or satisfaction, of God’s righteous requirement. God was pleased with the sacrifice and then gave the promise to never again destroy every living creature with a flood.
In Leviticus, a pleasing aroma is mentioned in connection with the various offerings of Jewish tabernacle worship. Leviticus 1:9 says, “The priest is to burn all of it on the altar. It is a burnt offering, a food offering, an aroma pleasing to the LORD.” As in the case of Noah’s offering, what pleased the Lord was the commitment to offer worship in His name as He commanded. The “pleasing aroma” is also mentioned in Leviticus 1:9 and 13, emphasizing the action of propitiation rather than the actual smoke of the burnt offering.
The same is true in Leviticus 2 regarding the grain offering. Despite the fact that this offering involved grain rather than meat, it had “an aroma pleasing to the LORD” (verse 2).
Even the larger sacrifice at the yearly Feast of Weeks focused on the redemption of sinners as the reason for the pleasing aroma. Leviticus 23:18 states, “Present with this bread seven male lambs, each a year old and without defect, one young bull and two rams. They will be a burnt offering to the LORD, together with their grain offerings and drink offerings—a food offering, an aroma pleasing to the LORD.”
Offerings made to false gods were also described as having a “pleasing aroma”—to the idols, at least (Ezekiel 6:13, ESV). The smell of the incense may have been appealing to the idolaters who offered it, but such false worship displeased the Lord, who demanded worship only of Him and sacrifice only to Him.
The New Testament reveals Christ as the final sacrifice for sin, the ultimate propitiation: “Christ loved us and gave himself up for us as a fragrant offering and sacrifice to God” (Ephesians 5:2). Jesus, the Son of God, was the only One who could provide the eternally pleasing sacrifice. He alone is the One of whom the Father says, “You are my Son, whom I love; with you I am well pleased” (Mark 1:11).