The sweet smell in the nostrils of god is the honoring of Christ, the savior that brings peace between man and God.
As individuals bow in humility and worship, their sacrifice was a sweet smell to god.
The stench in God's nostrils is also known as the Sin's Stench.
The Lord God smells sin from heaven and it is described in Scripture as an unpleasantly-smelling smoke in His nostrils (Isaiah 65:5).
However, on the day of your conversion God gave you a bath.
He washed you by the cleansing blood of Christ and the spiritual washing of the Spirit (1 John 1:7; Titus 3:5).
In Isaiah, God indicted the haughty and vain daughters of Zion, saying He'd strip them of their finery, “Instead of a sweet smell there will be a stench.”
Isaiah 3:24 Sin stinks to high heaven.
Sin screams and moans and shrieks its awfulness to God.
Twice per day, morning and twilight, the priests burned incense and met with the Lord.
God had a “signature” scent which we know contained frankincense, but the other ingredients remain debated.
And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.
And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed.