Jesus teaches that we should pray and have full faith in answered prayers:

“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

“Now faith is the substance of things hoped for, the evidence of things not seen.”

Hebrews 11:1

The eyes of faith see further than the physical eyes, for they see the answer to prayer before it manifests in the physical life. If you are sick, think of yourself as healed and confess: “I see myself healed by Jesus’ wounds.” Let this be your daily confession until the truth manifests in your physical body. 

About God it says:

“God, who gives life to the dead and calls those things which do not exist as though they did.”

Romans 4:17

“By faith we understand that the worlds were framed by the word of God, so that the things which are seen were not made of things which are visible.”

Hebrews 11:3

“For He spoke, and it was done; He commanded, and it stood fast.”

Psalm 33:9

Let's do the same as God. When you act according to God's will, you can call those things which do not exist as though they are. God said, “Let there be light,” and there was light.” God spoke before it happened, before the light shone. His words had creative power.

Jesus says:

“Assuredly, I say to you, whoever does not receive the kingdom of God as a little child will by no means enter it.”

Mark 10:15

Do we need to learn simple, uncomplicated childlike faith so that God's power can begin to work?