When God created man he said, "It is not good that man should be alone." 
There are times to be alone and there are times to be with other people. 
Praying with a prayer partner is one of those special times in our lives 
when the Lord is very present.  

Moses had Aaron and Hur (Exodus 17:10) to assist him in prayer warfare. 
Elijah needed an Elisha by his side to be encouraged that he was not the 
lone prophet. Shadrach, Meshach, Abednego prayed in the firey furnace and 
Jesus joined them. Jesus often prayed with Peter, James and John. They 
had a prayer partnership. Later we see Peter and John going to the 
Temple together at the hour of prayer. Two disciples walked together on 
the road to Emmaus and their hearts burned within them as the Lord 
joined in their conversation. 

Matthew 18:19-20
If two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven. For where two or three are gathered together in my name, there am I in the midst of them.

Ecclesiates 4:9-12
9 Two are better than one; because they have a good reward for their labor. 10 For if they fall, the one will lift up his fellow: but woe to him that is alone when he falls; for he has not another to help him up. 11 Again, if two lie together, then they have heat: but how can one be warm alone? 12 And if one prevail against him, two shall withstand him; and a threefold cord is not quickly broken.

Malachi 3:16
God even keeps a record of those who often speak one to another of Him.
Then they that feared the LORD spoke often one to another: and the LORD hearkened, and heard it, and a book of remembrance was written before him for them that feared the LORD, and that thought upon his name. And they shall be mine, says the LORD of hosts, in that day when I make up my jewels; and I will spare them, as a man spares his own son that serves him.