Mark 11:23

For verily I say unto you, that whosoever shall say unto this mountain, be thou removed and 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. 

In the beginning, God spoke the word and created heaven and earth.  God wants us to follow His example and confess our faith for healing, finances, wisdom, protection, or any need that lines up with His word.  Did you notice Jesus said saith or say three times in the above passage?  Believing and speaking opens doors by faith.