What were the tabernacle furnishings a picture of?
Everything depicted in the tabernacle experience—all its material and furniture, including the Ark of the Covenant, candlestick, altar of incense, table of showbread, brazen altar, and cleansing labor—was a picture of Christ in His work of redemption. This is what propitiation means: Christ's complete work accomplished by His death, burial, and resurrection.
Les explains that propitiation is best defined by what the tabernacle pictured: the building materials, the Ark of the Covenant, the candlestick, the altar of incense, the table of showbread, the labor of cleansing, and the brazen altar. Every one of those furnishings pictures Christ in His work of redemption. Propitiation is that complete, overall work Christ accomplished by His death, burial, and resurrection. Paul then says God set forth Christ as this propitiation through faith in His blood, to declare His righteousness for remission of sins, so that He might be just.
And they shall make an ark of shittim wood: two cubits and a half shall be the length thereof, and a cubit and a half the breadth thereof, and a cubit and a half the height thereof.
Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;