I Corinthians 14:2 For he who speaks in a tongue does not speak to men but to God, for no one understands him; however, in the spirit he speaks mysteries.

I love the way the passion translation put the above verse: "When someone speaks in tongues, no one understands a word he says, because he’s not speaking to people, but to God—he is speaking intimate mysteries in the Spirit". You must make sure as a believer that you spend time building up on your most holy faith. 

The very advantage that the Lord Jesus spoke about that we have on earth is the Holy Spirit. The Holy Spirit is Jesus unlimited within a believer. There are mysteries that we don't know and wouldn't be able to properly communicate to God in prayer without the Holy Spirit. The short cut to these things is when we pray in the spirit. 

Because of limitations of man, most of the time, we can only pray based on what we can see physically, but there is more with God. Joseph would have simply just pray that Pharaoh one day would grant him presidential pardon, but then, he was there for another two years. But his destiny was the throne and leadership in Egypt. 

Romans 8:27 Now He who searches the hearts knows what the mind of the Spirit is, because He makes intercession for the saints according to the will of God.