And Jesus answering saith unto them, Have faith in God. For verily I say unto you, that 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.Therefore I say unto you, what things soever ye desire, when ye pray, believe that ye receive them, and ye shall have them.
I John 5:14-15
And this is the confidence that we have in Him, that if we ask any thing according to His will, He heareth us. And if we know that He hear us, whatsoever we ask, we know that we have the petitions that we desired of Him.