Genesis 8:20
And Noah builded an altar unto the LORD; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar. And Noah builded an altar unto the LORD; and took of every clean beast, and of every clean fowl, and offered burnt offerings on the altar.
The account containing this verse is an inspired record of real events, in which Noah was a literal person and the flood was a fact of history. That flood was a judgment brought upon the earth because of increasing sin. After being preserved through it, Noah built an altar to the Lord and offered burnt offerings from every clean beast and every clean fowl.
Those offerings expressed both gratitude to God for preservation and faith in Christ as the great sacrifice. God accepted the offering as a sweet savor and blessed Noah and his family. The days of Noah prefigure the age just before Christ appears in the clouds of heaven.
The altar and worship here prove God had a church as far back as the days of Noah and Abraham. Returning tithes and offerings to God is the Bible plan ordained from the first and a duty enjoined upon believers in all ages of the world. Tithes and offerings are God's means to carry forward His work on the earth and to impress on man that God is the giver of all blessings, requiring a portion of His bestowed gifts to be returned to Him. The requirement is not compulsion; as with God's holy Sabbath time, man must obey from a willing heart and not rob God by using for himself the time and portion the Lord has claimed as His. The first response to God's mercy and love should be grateful thanks and humble worship.