While Apollos was in Corinth, Paul traveled through the interior regions until he reached Ephesus, on the coast, where he found several believers. “Did you receive the Holy Spirit when you believed?” he asked them. Acts 19:1-2 (NLT)
Paul was traveling and he came across some believers. Now, one would assume that since they are believers, they received the Holy Spirit when they believed, right? But apparently something was off because Paul asks them about it. And they said "We don't even know what the Holy Spirit is."
What does it mean to receive the Holy Spirit? I like the way the MSG puts this verse. It says “Did you receive the Holy Spirit when you believed? Did you take God into your mind only, or did you also embrace him with your heart? Did he get inside you?” That seems like a really good explanation. Did you take God into your mind only or in your heart? I love the next line. Did he get inside you?
Doesn't that sum it up? We are promised that when we accept Jesus as our Savior we will receive the gift of the Holy Spirit. But what does it look like? Well, first it means something has to change. You can't live your old life of putting yourself first; God has to come first. Now, most of us aren't going to just start putting God first. Maybe that's why the Holy Spirit has to camp out inside us - forever. This putting God first thing usually takes some time and it is often a slow, gradual process.
The process is different for everyone because God's relationship with each one of us is unique. So how the Holy Spirit works in my life is going to look different than how he works in yours. Which is why we should never judge each other. But, according to the Bible the general process is that you accept Jesus, the Holy Spirit moves in, he starts talking to you about your choices, your priorities, and your behavior. You keep praying, reading your Bible, looking for God in lots of different ways (because a relationship is a two way street). The Holy Spirit uses what you are doing and what God is saying and you begin to see a difference in your life. Sometimes you can't see it all at once; sometimes you have to look back and realize that some things you used to do you don't do any more. Because you don't want to. That is the Holy Spirit.
His job is to keep growing you and teaching you and changing you to be more like God. Will you ever be finished before Jesus comes? Nope. And that's OK. God knows that. But he's in it for the long haul.
And I am certain that God, who began the good work within you, will continue his work until it is finally finished on the day when Christ Jesus returns. Philippians 1:6 (NLT)