What is the Power of God?
The Answer: The Power of God is the evidence or sign given by God to reveal or to show that HE is God. Here are few example from the Bible:
And when he was come into the temple, the chief priests and the elders of the people came unto him as he was teaching, and said, By what authority doest thou these things? and who gave thee this authority? (Matthew 21:23)
The Chief Priests and the Elders had every rights to demand this of Jesus because they themselves were choosen by God for the services in the Temple.
The Mystery of the whole matter is:
The Gospel is the Power of God!
How?
Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures: (1 Corinthians 15:1-4)
Known unto God are all his works from the beginning of the world. (Acts 15:18)
Now I tell you before it come, that, when it is come to pass, ye may believe that I am he. (John 13:19)
For I am not ashamed of the gospel of Christ: for it is the power of God unto salvation to every one that believeth; to the Jew first, and also to the Greek. (Romans 1:16)