Now He which stablisheth us with you in Christ, and hath anointed us, is God… – 2 Corinthians 1:21

We are consecrated to the Lord, for the oil poured upon the priest was the oil of consecration. From that time forward he was a dedicated man; he could not serve anyone but God; he, above all the rest of the congregation, was the man of God for ever as long as ever he lived. So beloved, we have been consecrated: the Spirit of God has sanctified us and set us apart unto the Lord, as it is written, “Ye are not your own; ye are bought with a price.” Our Lord said in His matchless prayer, “they are not of the world, even as I am not of the world.” “Sanctify them,” said He, “by Thy truth, Thy word is truth.” Yes, blessed be God, we are consecrated men and women: we belong to the Lord, and are vessels for the Master’s use, hallowed from all other uses to be the Lord’s. “For I will be to them a God, they shall be to me a people.” Does not this make you glad? Are you really set apart to be the Lord’s own sons and daughters, and hallowed to be used by Him in His service both here and hereafter, and do you not rejoice? O my soul, dost thou not feel the trickling of the consecrating oil adown thy brow even now, and does it not make thy face to shine and make thy heart happy, because thou art now the Lord’s?

…And it is this anointing which teaches us and makes us fit for the service to which the Master has called us. Oh, does the Holy Spirit then lead us into all truth, and give us knowledge, and shall we not rejoice? Ignorance means sorrow, but the light of the knowledge of God in the face of Jesus Christ means joy. O brethren, will ye not bless God to-day for what the Spirit of God has taught you? If you do not, what must you be made of? for He has taught you such wonderful lessons so full of joy. Even if He has never taught you more than this, that whereas you were once blind now you see, He has taught you enough to make your heart rejoice as long as you live. Is He not the oil of gladness? ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/1273.cfm