Praying in the spirit is one of the dividing lines between charismatic and denominational Christians. The Charismatics have made people feel like if you not praying in tongues, you're not as spiritual as you should be. And some denominations teach their folks that tongues is of the devil. I personally pray in tongues almost daily, for reasons I'll list below. I first want to show you a few passages on the topic.
JESUS SAID YOU WOULD DO IT
Mark 16:17 And these signs will accompany those who believe: In my name, they will drive out demons; they will speak in new tongues
Jesus said that people who believe in his authority/name would do it. That's a pretty significant point.
1 Corinthians 14:2 For anyone who speaks in a tongue does not speak to people BUT TO GOD. Indeed, no one understands them; THEY UTTER MYSTERIES BY THE SPIRIT. 4 Anyone who speaks in a tongue EDIFIES THEMSELVES, but the one who prophesies edifies the church. 14 For if I pray in a tongue, MY SPIRIT PRAYS, but my mind is unfruitful.
1 Corinthians 14 gives us insight into what's going on when we pray in tongues/spirit.
You are speaking to God
You are uttering mysteries by the spirit
You are edified (built up, strengthened)
Your spirit is praying
Paul makes it clear that praying in the spirit/tongues is mostly for personal benefit. He gives us the instruction that if someone prays in the spirit in a congregational setting, someone should interpret it. If there's no interpretation, stick to a language everyone in the room understands.
GOD DOESN'T MAKE YOU DO IT
A common misconception is that God takes over your mouth when you pray in tongues. While you may experience a powerful yielding to God's spirit as you pray, God is not taking over.
The first time believers experienced tongues was at Pentecost in Acts 2.
Acts 2:4 KJV And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.
If you diagram this sentence you'll see that THEY spoke, as the spirit gave them utterance. The people are doing the speaking, but God gives the utterance.
GOD DECLARES HIS GLORY THROUGH YOU
The word utterance is the Greek word apophtheggomai, which means to speak out, speak forth or pronounce. Apophtheggomai is not a word used in everyday speech, but one belonging to dignified and elevated discourse. The application of the word is to "declare oneself" or "give one's opinion."
When you put all that together, it simply means that you're speaking out by faith, yielding your speech to God's influence and he begins to declare himself through you. Specifically, he declares his opinion through you.
Many of you know the Greek word for glory is doxa. Doxa means "one's view and opinion." Add that bit of understanding and you're brought to the idea that praying in tongues is collaborating with God as he declares his glory through you. Powerful!!
Why can't God just take over and make you pray? Because he gave mankind dominion over their own bodies and this planet. God works through men to accomplish his will. Praying in the spirit is when you mix your earthly authority with God's heavenly authority and he declares his truth to this realm through you. This realm is designed to respond to the authority of mankind. Tongues is allowing God to speak on your behalf to this created realm. It's as if you're giving God permission to speak on your behalf, through you. Operating the gift of tongues is allowing God to pray for you, through you.
STIR UP THE GRACE WITHIN
In 2 Timothy 1:6 Paul reminds young Timothy to "fan into flame (stir up) the gift of God, which is in you." He's reminding his pupil to not grow weary, that he needs the power of God flowing through him. Tongues does exactly this, it stirs up the grace, the inner man that is connected to God, and allows God to flow more freely through a believers heart.
Tongues is not convincing God to do something, it's more like taking the cork out of the bottle and letting the spirit flow. The spirit of God dwells in full within every believer, but we must allow ourselves to be filled with his spirit or under the influence of his spirit for his power to affect our non-spiritual being; body, soul, mind, circumstances...
CORRECTING A MISCONCEPTION
The following passage is probably one of the misused passages in the Bible. How many times have you heard someone say "all things work together for good?" Or some version of that.
Romans 8:26 In the same way, the SPIRIT HELPS US IN OUR WEAKNESS. We do not know what we ought to pray for, but THE SPIRIT HIMSELF INTERCEDES FOR US through wordless groans. 27 And he who searches our hearts knows the mind of the Spirit, because the Spirit intercedes for God’s people in accordance with the will of God. 28 And we know that in all things God works for the good of those who love him, who have been called according to his purpose.
This passage is only applicable for the believer who loves God and allows him to intercede through them (praying in tongues). This passage is only for those who allow God by faith to work in that circumstance and turn it for their good. In no way can we apply in a blanket way the erroneous concept that God makes every circumstance on the planet work out for good for his obscure purposes.
You cannot randomly apply this concept to cancer, job loss, injustice in the world and bad politics. This passage clearly says that God can work through all things for people who love him and allow him to intercede for them. He can't just make every situation work for good because mankind has dominion over this planet and God will not go against his original declaration.
IT DOESN'T FEE REAL
Have you ever tried to pray in tongues but it didn't feel real? Or it felt like nothing happened? Or you felt silly? Join the club, everyone feels that way the first few times.
Remember your spirit is praying and your mind won't get it (1 Corinthians 14:14). The key is to mix faith in your heart with the sounds in your mouth. Jesus addressed this concept in Matthew 15:8 "These people honor me with their lips, but their hearts are far from me." While this passage is not about tongues, the principle applies. When you pray in tongues, make sure you start with gratitude and an awareness of God's spirit within. Remember that it's an act of faith, you're doing something that doesn't make sense to your mind but you can be confident, knowing that God is praying for you, through you.
If you pray in tongues, good! Do it more! The world around you needs to hear from God through you. If you do not pray in tongues, put yourself in a worshipful state of mind, become aware of his spirit within and step out in faith. You should expect to feel better after your spirit prays.
I can't tell you how many stories of things working out for people after they prayed in the spirit over a particular issue. Sometimes it's instant, in the form of wisdom, sometimes it's much later. I want to encourage you to not give up, stick with it. Trust that God is interceding for you, through you. Make the decision that you'll yield to God and allow him to declare the glory of his name through you to affect the world around you.