Jesus said, "Again, I tell you that ifi two of you on earth agree about anything you ask for, it will be done for you by my Father in heaven. For were two or three come together in my name, there am I with them." (Matthew 18:19-20 niv)
It is sad how many Christians do not understand the great truth in what Jesus promised right there. They miss out on tremendous power to pray for great and mighty deeds, and to see God do them!
It is good for us to pray alone and often, but it is still better for us to get together with other believers, to agree on what to pray for, and to pray together of one mind - knowing that Jesus is present with us when we do. Nothing can stop a little group (or large group) of Believers who are in harmony with one another, loving and forgiving one another, who have discerned God's will in a matter, and are agreed on what they should to ask God to do. If they join hearts and minds and mouths, to pray unitedly about what they know to be God's will, then Jesus says He'll be there praying with them, and God in Heaven will do what they request.
Since the day the disciples were gathered in one room praying for the Holy Spirit, whom Jesus had promised before He rose up into the sky and went back to Heaven, and when the Holy Spirit came upon them as living tongues of fire on their heads, - since that time many more marvelous things have been done through the prayers of believers praying together in one accord.
What kind of things?
* 3000 souls were saved that day!
* The Church, the Body of Christ, grew by leaps and bounds and still does now, more than 2000 years later!
* Many believers have held onto their faith, though martyred for it.
* Tremendous revivals have broken out at different times and places.
* Wicked governments have fallen. New nations founded.
* The sick have been healed, the demon-possessed have been delivered.
(and many more answers to prayer!)
Notice that these are not selfish requests. They are the kind of things that Jesus would pray for if He were in your place.
Even if you know all these things, you may still hesitate, or not want to pray together with others. Generally that means we are thinking too much of ourselves, and comparing ourselves to others. We think we cannot pray as beautifully as others, or that they will look down on us. We are afraid our honest emotions will show for all to see and hear.
This is another reason why it is so very important to have good prayer times alone with God, and often. We need to learn to love Him more than anyone else. We need to see ourself the way God sees us. That will heal us of insecurities, and change our focus on our shortcomings to focus on God's power and love. But then we also need to be brave enough to start to pray together with others - just one or two other Believers. The more often we do, the more we will enjoy the benefits of praying with others, and learn to love it.
Satan wants to make us isolated, to feel as if we are the only one in the world with our problem. Nobody else understands or cares about us. We must overcome that to be spiritually strong and mighty in our prayers. So if you are feeling too shy or wounded to pray with others in a group or in church, look for one or two Christian friends, and ask them to help you learn to pray. Ask Jesus to help you too! Ask Him every day. Then keep trying to pray together with others. Think of yourself as a disciple or student of Jesus, who must learn the basics before you can learn the advanced things in the Christian life.
If you are a new Christian, think of yourself as a baby Christian, who needs to learn to eat and eventually walk and talk. Human newborns don't learn all that in the first week of their life. It can take months, even years. A bright and willing person who becomes a Christian can grow faster than that, but some do take years, and sadly, there are many Christians who are still in the baby stages even though many years have passed in their human life since they were born again.
Make it a goal to learn to pray together with others. Then you will see miraculous answers to prayer!