In Hebrews 1:3 we read how the Lord Jesus Christ, “when He had by Himself purged our sins, SAT DOWN on the right hand of the Majesty on High”. The tenth chapter of the same book tells us why He sat down:
“Every 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 …FOR BY ONE OFFERING HE HATH PERFECTED FOREVER THEM THAT ARE SANCTIFIED” (Heb. 10:11-14).
There were several articles of furniture in the Old Testament tabernacle, but no chair. The priest could not sit down, for the work of redemption was not yet finished. His daily sacrifices only emphasized the fact that “it is not possible that the blood of bulls and of goats should take away sins” (Heb. 10:4).
“But this Man [Christ Jesus] sat down”, because by His death on Calvary — by that one offering — He paid for all our sins and “obtained eternal redemption for us” (Heb. 10:12; 9:12).
This is why Paul, by divine inspiration, now insists that salvation is “by grace”, that “it is the gift of God”, received “by faith” and “not of works, lest any man should boast”.
God has much for His people to do, but before we can do anything for Him we must learn to trust Him for our salvation, to rest in the finished work of Christ. God is satisfied with Christ’s 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:
“There remaineth therefore a REST unto the people of God, FOR HE THAT HAS ENTERED INTO HIS [God’s] REST, HE ALSO HATH CEASED FROM HIS OWN WORKS, AS GOD DID FROM HIS” (Heb. 4:9,10).
“Unto him that worketh not, but believeth on Him that justifieth the ungodly, his faith is counted for righteousness” (Rom. 4:5). source