Summary: The anointing of the Holy Spirit empowers the Spirit-filled believer for multiple, powerful ministries.
1 Samuel 16:12-13 So he sent and had [David] brought in. He was ruddy, with a fine appearance and handsome features. Then the LORD said, “Rise and anoint him; he is the one.”  So Samuel took the horn of oil and anointed him in the presence of his brothers, and from that day on the Spirit of the LORD came upon David in power.
•• In the Old Testament and the New Testament alike, the anointing spoke of a special action and empowerment by the Holy Spirit.
•• The future king David was anointed with oil by God's prophet. That was the outward expression. But what happened inwardly was far more important. The power of the Holy Spirit came upon him to equip him for the future God had for him.
2 Corinthians 1:21-22 Now it is God who makes both us and you stand firm in Christ. He anointed us,  set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come.
•• First, let it be established that God anoints His people. “He anointed us” — King David, the apostle Paul, you, me, and millions more from then to now receive this Holy Ghost anointing from God.
• Again, for what purpose does He confer upon us this anointing, this "unction" of His Holy Spirit?
Acts 1:5,8 ...in a few days you will be baptized with the Holy Spirit...  you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth.
•• One purpose of the Holy Spirit anointing — which comes in the baptism with the Holy Spirit (Acts 1:5,8; 2:1-4) — is to give us power to “be [Christ’s] witnesses”.
• Many Christians fear witnessing because they think they have to do it with their own natural abilities, their own persuasive power, etc.
• No! — “You will receive power[to be His witnesses] when the Holy Spirit comes on you.” There are no powerless Christians when they are filled with the Holy Spirit and walking in the anointing of God.
• The Holy Spirit, the anointing, makes you a good witness.
Luke 4:18-19 The Spirit of the Lord is on me, because he has anointed me to preach good news to the poor. he has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed,  to proclaim the year of the Lord’s favor.
•• In this verse five purposes of the anointing are revealed:
(1) to enable you “to preach [the] good news” effectively. The news we share about Jesus is “good”. The anointing will enable you to share it with impact.
(2) to make you a Spirit-filled messenger, a “proclaim[er of] freedom for the prisoners” — freedom from the prison of sin, of drugs, of depression, of life-dominating habits.
(4) You are anointed “to release the oppressed”. All around you are people oppressed by sin, by sickness, by demonic attacks, etc. You have a message of release for them.
(5) You are anointed “to proclaim the year of the Lord’s favor” to people ignorant of the comforting message of God's grace.
Acts 10:37-38 You know what has happened throughout Judea, beginning in Galilee after the baptism that John preached —  how God anointed Jesus of Nazareth with the Holy Spirit and power, and how he went around doing good and healing all who were under the power of the devil, because God was with him.
• This Greek word root for “doing good” occurs only twice in the New Testament, and its meaning is that of a philanthropist or benefactor.
• Vine’s defines it as “to bestow a benefit...”
• The anointing is not just for healing, preaching, witnessing, delivering, and miracle-working power. It is also to empower us to be benefactors, doers of good, to needy people.
• Mother Teresa must have had a powerful anointing!
•• On the spiritual side, the anointing gives you power to break the devil’s yoke in people’s lives.
1 John 2:20, 26-27 But you have an anointing from the Holy One, and all of you know the truth....  I am writing these things to you about those who are trying to lead you astray.  As for you, the anointing you received from him remains in you, and you do not need anyone to teach you. But as his anointing teaches you about all things and as that anointing is real, not counterfeit — just as it has taught you, remain in him.
•• Finally, the anointing empowers us to hear, discern, and hold to truth (vs. 20) — “You have an anointing ... and ... know the truth.”
• This does not nullify the ministries of God-anointed pastors and teachers (Ephesians 4:11). Rather, the context (26) is in contrast to false teachers.
• The Holy Spirit's anointing will help you sort out false teachers and false teachings.
• “This anointing teaches you” — the believer is properly encouraged to read the Bible for him or herself. As they do so, the Spirit of God brings illumination and clarity.
In sum, we are anointed for many purposes, including:
• to have power to be effective witnesses
• to enable us to share the Good News about Jesus Christ
• to proclaim freedom for the prisoners
• to bring recovery of sight for the blind
• to release the oppressed
• to proclaim the Lord’s favor and grace
• to be benefactors, doing good to needy people
• to break the devil’s yoke in the lives of bound-up people
• to teach us and help us know God’s truth versus error