 When you go to pray, do you realize that you're acting on the desire the Spirit gave you? And that without the Holy Spirit, you wouldn't even want to pray. This is why it amazes me when people come before God wondering if He really wants to accept them. They say things like, well, I want to talk to God, I want to pray, I want to go into His presence, I want to sit with Him, but I don't know if He really wants to see me right now. The fact that you want to means He does do. The desire to pray is itself an invitation to prayer.