The Bible says in Hebrews 10:23, "Let us hold fast the profession (confession) of faith without wavering; for He is faithful that promised."
 
Confession in the Greek means to "Say the same thing as" to say the same as what? To say the same things that God says in His Word. Confession then is just agreeing with God and saying the same things as He has said in His Word.
 
Jesus said in Mark 11:23, "Whosoever shall SAY unto this mountain, be thou removed and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he SAITH shall come to pass; he shall have whatsoever he SAITH."
 
You can have what you SAY! Base your confession on the Word, e.g. the Bible says that God has not given us a spirit of fear, but of  power and of  love and of a sound mind, so, when fear comes upon you, begin to confess "God has not given me the spirit of fear, so fear I Resist you in the name of Jesus." Find out what the Word has to say  about healing, prosperity, victory, and about who you are in Christ, then begin to confess them with your mouth and they will become a reality to you.
 
There is power in the tongue! Proverbs 18:21 says, "Death and life are in the power of the tongue." Proverbs 15:4 says, "A wholesome tongue is a tree of life." And Proverbs 12:18 says, "The tongue of the wise is health."
We can see from these verses how powerful the tongue is! With it we can produce death or life, sickness or health, faith or fear. Proverbs 6:2 says, "Thou art snared with the words of thy mouth, thou art taken with the words of thy mouth." What you are today is a result of what you said yesterday! If you say you can't, then you can't, if you talk doubt, then you will have doubts. If you say you will be sick, then you will be sick, if you say that nothing good ever happens to you, then nothing good  will ever happen to you..
 
Your faith will never rise above your confession! Your confession will not be right until your mind is renewed to the Word of God. You renew your mind by reading and meditating the Word of God.
 
In Mark 11:23, Jesus told us what faith is and how faith works. Faith is believing in your heart and it works by the confession of your MOUTH. This is how you got saved, Romans 10:10, "For with the heart man believeth unto righteousness; and with the MOUTH CONFESSION is made unto salvation."
Notice that there must be a heart and mouth harmony. Jesus said, what a man has in his heart he will say with his mouth cf Luke 6:45. Romans 10:8 says, "But what saith it? The word is nigh thee even in thy MOUTH, and  in thy HEART: that is the word of faith, which we preach."  Notice again HEART and MOUTH. Believing in your heart and saying it with your mouth will always get results!
 
The miracle that you need is in your mouth, when you give confession to the Word of God it sets in motion the miracle action which is in the Word. God has promised in Jeremiah 1:12 "To watch over his Word is to perform it," THE MOMENT THE WORD COMES OUT OF YOUR MOUTH, GOD IS WATCHING OVER IT TO MAKE IT GOOD IN YOUR LIFE!

Let us go back to our text Heb 10:23 "Let us hold fast the confession of faith." We must understand that we have to hold fast to our confession. When it looks like it is not going to work, when there seems no hope, when people are telling you to quit, that's the time to HOLD FAST to your confession of faith and not to quit! 

If you have been holding fast a confession of faith, but then you get fed up of standing in faith, so you decide to quit. What you do is commit spiritual abortion, you abort the Word, you stop the miracle action of the Word. The sad thing is that if you had stood for another day or so you would have your miracle manifested.

Remember, the darkest hour is just before dawn!

The Word must be allowed to go it's full cycle. Jesus said in Mark 4:28, "For the earth bringeth forth fruit of herself; first the blade, then the ear, after that the full corn in the ear." Jesus said that the Word is seed. When that seed is sowen in the heart, and if the soil of the heart is good soil then that seed will bring forth fruit, but it must go it's full cycle first.

In Mark chapter four Jesus shows us what we call, "The law of progression" this law begins by sowing the Word in your heart, this can be done by reading the Word, speaking the Word, hearing the Word, and by meditating on the Word. Once the Word is in the heart, faith comes (See Romans 10:17) then when you speak the Word in faith, that motion; the "MIRACLE ACTION" begins to change situations. Circumstances start to change, your body begins to get well, God is performing His Word, first there will be the blade, then the ear, and then, bless God the FULL CORN IN THE EAR!

Holding fast is not quitting when you see the blade or the ear! You hold fast until you see the FULL CORN in the ear, but even before you start to see any sign of a change, faith says, "It's mine, I have it now."