There are many misconceptions about the identity of the Holy Spirit. Some think of Him as a mystical, cosmic force at work in the universe. Others see Him as an impersonal energy source that God utilizes from time to time as He sees fit. Still, others render the Holy Spirit as a depersonalized emanation from God. However, the Bible declares Him as God.
The Holy Spirit is one member of the Trinity or Godhead and is co-equal with God the Father and Jesus Christ. He possesses all the attributes and characteristics of God and actively participated in Creation, the incarnation, and the resurrection of Jesus from the dead. As God, He is to be honored, revered, and obeyed as He serves the Father and Son in perfect unity.
The Holy Spirit is a Helper, Teacher, Comforter, and Counselor. He plays an active role in each person’s salvation by convicting them of their sins and convincing them of God’s righteousness and judgment. He also distributes spiritual gifts to believers as He determines and produces spiritual fruit and maturity within them as they obey Jesus and live for God’s glory.
The Holy Spirit does not "come upon" believers only to depart later, like in the Old Testament. He is a permanent fixture within believers' hearts for eternity. His indwelling presence was not the result of them obeying the Ten Commandments, performing good works, becoming water baptized, or partaking in biblical ordinances. It resulted from them trusting Jesus by faith for their salvation, which is His only means of entrance. Once inside, His presence acts as a deposit, guaranteeing believers' eternal life and their glorification at the resurrection.
(See the Scripture References link at the top of the page.)