What does the Holy Spirit do?

 

“This third Person is called, in technical language, the Holy Ghost or the ‘spirit’ of God. Do not be worried or surprised if you find it (or Him) rather vaguer or more shadowy in your mind than the other two. I think there is a reason why that must be so. In the Christian life you are not usually looking at Him. He is always acting through you. If you think of the Father as something ‘out there’, in front of you, and of the Son as someone standing at your side, helping you to pray, trying to turn you into another son, then you have to think of the third Person as something inside you, or behind you.” – C.S. Lewis in Mere Christianity