I am debtor both to the Greeks, and to the Barbarians; both to the wise, and to the unwise. So, as much as in me is, I am ready to preach the gospel to you that are at Rome also. 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. For therein is the righteousness of God revealed from faith to faith: as it is written, The just shall live by faith.
Romans 1:14-17
When we think about God's unlimited power, one of the first and most obvious demonstrations is creation. Simply by speaking it into existence God created the world out of nothing. “Let all the earth fear the LORD: let all the inhabitants of the world stand in awe of him. For he spake, and it was done; he commanded, and it stood fast” (Psalm 33:8-9). Another commonly-thought of display of God's power is the miracles we see both in Scripture and in our own lives. God is not bound by what is possible for us. He has all power, and is able to work in whatever way is needed to accomplish His purpose. The seas can part, the sun can stand still, the barren can have children and the overwhelming enemies can be defeated.
Often people do not think of the gospel in terms of it being a demonstration and display of God's power, but there is no greater miracle than a child of the devil who is lost and headed for eternity in Hell to become a child of God who is saved and headed for eternity in Heaven. That kind of transformation is beyond any human power but it poses no challenge for God. “When his disciples heard it, they were exceedingly amazed, saying, Who then can be saved? But Jesus beheld them, and said unto them, With men this is impossible; but with God all things are possible” (Matthew 19:25-26).