Again I say to you that if two of you agree on earth concerning anything that they ask, it will be done for them by My Father in heaven. “For where two or three are gathered together in My name, I am there in the midst of them.
(Matthew 18:19 -20)

When you are in complete agreement with the Word of God and in full trust with the Lord Jesus Christ. You have then opened the door for the power of God to be released in your life.. Agreement with the Lord Jesus means you fully believe His promises and Word.

And when He had come into the house, the blind men came to Him. And Jesus said to them, “Do you believe that I am able to do this?” They said to Him, “Yes, Lord.” Then He touched their eyes, saying, “According to your faith let it be to you.”) Faith and Belief with Trust in God means you are in complete agreement with Him.
(Matthew 9:28-29)

In Mark 9:23 Jesus said to him, “If you can believe, all things are possible to him who believes.”  It pleases God when you trust and believe Him with a full agreement with His Word.  God Almighty will never do anything contrary to His written Word.  When your prayer agrees with His Word and you trust him to fulfill it the miracles will flow freely in your life!

But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him.)
(Hebrews 11:6)
Therefore I say to you, whatever things you ask when you pray, believe that you receive them, and you will have them.
(Mark 11:24)
Delight yourself also in the LORD, And He shall give you the desires of your heart.
(Psalm 37:4)
Commit your way to the LORD, Trust also in Him, And He shall bring it to pass.
(Psalm 37:5)
I am the vine, you are the branches. He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing.
(John 15:5)
If you abide in Me, and My words abide in you, you will ask what you desire, and it shall be done for you.
(John 15:7)