The Bible often refers to the Holy Spirit as a gift. Not once is the Holy Spirit portrayed as a power that can be earned or bought.
In Acts 8:18-21 a guy by the name of Simon tried to buy the power of the Holy Spirit from Peter and Peter essentially told him that as far as he was concerned Simon could perish with his money. Simon was shaking in his boots and ended up begging Peter to pray that none of those bad things would happen to him.
It may seem ridiculous to try buying the power of the Holy Spirit with money, but I've noticed that we get about as silly with our attempts to earn the "gift of the Holy Spirit". People try to discover the perfect formula to encounter God's Spirit and end up with a whole list of techniques designed to earn the power of the Holy Spirit.
Sometimes we have an experience with God's Spirit and we conclude that we just need to duplicate whatever we were doing in order to make God move again. Some form of legalism is sure to follow.
We can certainly do things that invite Him to work and we can do things to keep him from working in our life, but we can never force God to obey us because we think that we've earned it.
Our part is to receive the gift of God's Spirit in faith. Hardly a day goes by that I don't ask God for more of His Spirit at work in me. I can't earn it but I will let God know that I want His best gifts for me.I believe that God is always looking for people who come in simple faith asking Him to fill them with the gift of His Spirit.