God's sure mercies are the resurrected Christ who did not see the corruption of death and became the base of God's justification to His believers. This heavenly language is spoken in Acts 13:34-39. We need to study these six verses again and again. Otherwise, we will not be able to enter into a proper understanding of them. We all have been sanctified, but sanctification needs a base, and the base of sanctification is justification. If you are not justified, you can never be sanctified.
Christ is God's sure mercies for our sanctification. For this He also became the base of justification in His resurrection. Paul said in Acts 13 that it is by this Man, Jesus, who is the mercies of God, that we can be justified. Thus, justification is based upon the resurrected Christ who has never seen the corruption of death. Acts says that death cannot hold Him. That means death cannot touch the resurrected One. Such a resurrected One, Jesus, is the foundation, the base, of our justification. Based upon such a justification in Christ's resurrection, we are enjoying Christ as the mercies which sanctify us.
We should not forget that the resurrected Christ today is the sure mercies of God to us. He has become the base of our justification, and upon this justification something is built up, that is, sanctification. Furthermore, sanctification is something built with and by the sure mercies of God. These sure mercies are Christ.
Christ as the sure mercies of God has been appointed a Witness to the peoples, nations (Isa. 55:4a). Revelation 1:5a says that Christ, the second person of the Divine Trinity, is the faithful Witness of God. He is the Witness of the entire Godhead. Revelation 3:14a also says that He is the faithful and true Witness. Christ is the Witness to testify the true God.
He has been appointed a Leader and a Commander to the peoples (Isa. 55:4b; Acts 5:31a). He is the Leader above all the kings, the Leader above all the rulers. This is for His administration. He has also been appointed a Commander. He is the General to fight the battle. When He returns, He will fight in the war at Armageddon (Rev. 19:11-21). He will be the Commander, the fighting General, to defeat the biggest army on earth with Antichrist as the opposing commander.