Holy Spirit ─ From the very beginning of Genesis, the breath of God (ruah in Hebrew) is designated as the sign and beginning of all life, including for Adam who becomes alive when God breathes into him a "breath of life" (Gen 2:7). 

What the Bible says about the Holy Spirit

Jesus sent the Holy Spirit after he left the earth. It is for our good that Jesus left and sent the Holy Spirit. The Holy Spirit is our defender. The Holy Spirit convicts us of sin. The Holy Spirit is the Spirit of truth and leads us into all truth. The Holy Spirit reveals the glory of Jesus.

The Holy Spirit is God Himself (and not simply an idea or a force) and we have a relationship with Him equivalent to that which we have with God the Father and God the Son. When Jesus ascended into heaven, he didn't leave us alone. 

Instead, He sent us the Holy Spirit to dwell in us, to fill us, to guide us, and to strengthen us. He has not left us orphans. On the contrary, the Holy Spirit is His constant presence with us.

Living by the Holy Spirit

The key to victorious Christian living is not to double our efforts. The key is not to just do more "Christian activities" just for the sake of doing them. Although Bible reading, prayer, Christian service, and similar activities are integral parts of our relationship with God, increasing our efforts in any of these areas will not save us or give us victory. Paul tried (Romans 7), but the result was defeat and frustration.

Instead, the key is to submit to the direction of God's Spirit and receive His power. The essence of the Christian life is God's work in us and through us, not the works we do for him. We are transformed into the image of Christ by the power of the Holy Spirit who dwells in us.

Some verses about the promise of the Holy Spirit

"As he was with them, he advised them not to leave Jerusalem, but to wait for what the Father had promised, which I announced to you," he told them; "for John baptized with water, but you, in a few days, will be baptized with the Holy Spirit." (Acts 1:4-5)

"Go, make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit, and teach them to observe all that I have commanded you. And behold, I am with you always, to the end of the world." (Matthew 28:19-20).

The coming of the Holy Spirit

"On the day of Pentecost, they were all together in one place. Suddenly there came a sound from heaven like a rushing mighty wind, and it filled the whole house where they were sitting. Tongues, like tongues of fire, appeared to them, separate from one another, and landed on each of them. And they were all filled with the Holy Spirit and began to speak with other tongues, as the Spirit gave them utterance" (Acts 2:1-4).

Walk with the Holy Spirit

"If we live by the Spirit, let us also walk by the Spirit." - Galatians 5:25.

Once we receive the Spirit, it is clear from this verse that there is a path we must walk. To walk in the Spirit means to be obedient to the Spirit. 

"Therefore I say, walk in the Spirit and you will not fulfill the desires of the flesh. For the flesh has desires contrary to the Spirit, and the Spirit has desires contrary to the flesh; they oppose each other, so that you do not do what you would like. - Galatians 5:16-17.

"So then, brothers, we do not owe it to the flesh to live according to the flesh. If you live according to the flesh, you will die; but if by the Spirit you put to death the deeds of the body, you will live. - Romans 8:12-13.

"Therefore, as the Holy Spirit says, Today, if ye will hear his voice, harden not your hearts, as in rebellion..." Hebrews 3:7-8.

The Results When We Walk in the Spirit

"But the fruit of the Spirit is love, joy, peace, longsuffering, kindness, goodness, faith, gentleness, self-control; the law is not against these things. - Galatians 5:22-23.

"...the affection of the Spirit is life and peace. - Romans 8:6.

"May the God of hope fill you with all joy and peace in the faith, that you may abound in hope through the power of the Holy Spirit!" - Romans 15:13.