In Hebrews 1:3 we read how the Lord Jesus Christ, βwhen He had by HimselfΒ purged our sins, SAT DOWN on the right hand of the Majesty on Highβ. The tenth chapter of the same book tells usΒ whyΒ He sat down:
βEvery priest standeth, daily ministering and offering oftentimes the same sacrifices, which can never take away sins: But this man [Christ] after He had offered one sacrifice for sins forever, SAT DOWN on the right hand of God β¦FOR BY ONE OFFERING HE HATH PERFECTED FOREVER THEM THAT ARE SANCTIFIEDβ (Heb. 10:11-14).
There were several articles of furniture in the Old Testament tabernacle, but no chair. The priestΒ could notΒ sit down, for the work of redemption was not yet finished. His daily sacrifices only emphasized the fact that βit is not possible that the blood of bulls and of goats should take away sinsβ (Heb. 10:4).
βButΒ thisΒ Man [Christ Jesus] sat downβ, because by His death on Calvary β by that one offering β He paid for all our sins andΒ βobtained eternal redemption for usβ (Heb. 10:12;Β 9:12).
This is why Paul, by divine inspiration, now insists that salvation is βby graceβ, that βit is the gift of Godβ, received βby faithβ and βnot of works, lest any man should boastβ.
God has much for His people to do, but before we can do anything for Him we must learn toΒ trust HimΒ for our salvation, toΒ restΒ in the finished work of Christ. God is satisfied with Christβs payment for sin and together the Father and the Son are depicted as seated in heaven because the work is done. And now God would have us simply trust Him, entering into His rest:
βThere remaineth therefore a REST unto the people of God, FOR HE THAT HAS ENTERED INTO HIS [Godβs] REST, HE ALSO HATH CEASED FROM HIS OWN WORKS, AS GOD DID FROM HISβ (Heb. 4:9,10).
βUnto him that worketh not, but believeth on Him that justifieth the ungodly, his faith is counted for righteousnessβ (Rom. 4:5). source