Seeing and believing in the spiritual realm make a difference in exercising faith. Peter walked on water by faith because he saw Jesus walking on water. At that moment he was filled with the faith of the Son of God Himself. Faith is a gift. Jesus acceded to his request:
Matthew 14:28 And Peter answered Him, Lord, if it is You, command me to come to You on the water. 29 He said, Come! So Peter got out of the boat and walked on the water, and he came toward Jesus.
Peter saw Jesus with physical eyes. In the burst of excitement and impulse he got out of the boat and walked on water. He may not have done it perfectly but he did it for those moments.
Did Jesus want him to get out and walk on water? Why did Jesus allow him? Because Peter said, “Lord, if it is You.” Jesus is Jesus their Lord. He could not deny this fact.
Jesus walks in the spiritual realm and physical realm with the same power and authority over both realms. Peter saw Him performing supernatural acts in the physical natural realm. When he asked Jesus, his Lord, for the same ability, Jesus gave him. Jesus has said, “Ask, and you shall receive.” Peter asked and received, even the power to operate in the supernatural and spiritual realm! (Matthew 7:7 Keep on asking and it will be given you; keep on seeking and you will find; keep on knocking [reverently] and [the door] will be opened to you.)
It took me a long time to understand, believe, and start practicing the amazing supernatural truth about faith in action.
Here is the Bible verse that has spoken to me several times lately.
Hebrews 11:6 Amplified Bible, Classic Edition (AMPC)
6 But without faith it is impossible to please and be satisfactory to Him. For whoever would come near to God must [necessarily] believe that God exists and that He is the rewarder of those who earnestly and diligently seek Him [out].