Jesus wasn't talking to us, He was talking to His apostles.
"In the first book, Theophilus, I wrote about all that Jesus did and taught from the beginning until the day when he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles whom he had chosen. After his suffering he presented himself alive to them by many convincing proofs, appearing to them during forty days and speaking about the kingdom of God. While staying with them, he ordered them not to leave Jerusalem, but to wait there for the promise of the Father. 'This,' he said, 'is what you have heard from me; for John baptized with water, but you will be baptized with the Holy Spirit not many days from now.'
So when they had come together, they asked him, 'Lord, is this the time when you will restore the kingdom to Israel?' He replied, 'It is not for you to know the times or periods that the Father has set by his own authority. But you will receive power when the Holy Spirit has come upon you; and you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the ends of the earth.'" - Acts 1:1-8
Obviously the Spirit is given to each of us, as St. Peter said in Acts 2:38-39, "Repent and be baptized, all of you, in the name of Jesus Christ for the remission of your sins and you will receive the gift of the Holy Spirit. This promise is for you and for your children, and for all who are far off, as many s the Lord our God will call to Himself."
And as for what the Spirit does for us, well Scripture says many things. The Holy Spirit is the evidence that we will be resurrected from the dead (Romans 8:11), it is the Spirit in us which we can cry out "Abba!, Father!" (Romans 8:15-16) and confess that Christ is Lord (1 Corinthians 12:3). The Spirit does empower us, but there's no promise that the Spirit being in us means we won't sin. The empowering of the Spirit Jesus mentions in Acts 1:8 is specifically to the Apostles, as these are the ones who will "be My witnesses", remember the book is called "The Acts of the Apostles" because it's about the things the Apostles did, about how the Apostles went out, preached, and spread the Gospel to every corner of the ancient inhabited (i.e. Roman) world. Note, also, that Jesus didn't promise His Apostles here that they would some how be free from sinning, in point of fact we know that they didn't because St. Paul in his letter to the Galatians talks about how he had to call out St. Peter for his cowardice and hypocrisy.
The Spirit in us is not the guarantee that we'll be anything other than sinners while alive here on earth with our mortality; the Spirit in us instead is the guarantee that we belong to Christ and that even in this body of death we have the confidence and conviction that even as God raised Christ from the dead, He will raise us up also. That we are in Christ and have God as our Father. It is precisely the life of the Spirit (Romans 8) that gives hope to the Apostle who in the previous chapter (Romans 7) cries out "what a wretched man I am!" because of the conflict and struggle between the new man and the old, "the good that I want to do I don't do and the evil I don't want to do I do"; that in spite of our mortality and the "law of sin" present in our members, we have hope in Jesus, and to walk in the life of the Spirit with our eyes fixed on that hope; that not only we ourselves, but all creation shall be made whole and restored on that future glorious Day.
-CryptoLutheran