For I too am a man set under authority, with soldiers under me: and I say to one, ‘Go,’ and he goes; and to another, ‘Come,’ and he comes; and to my servant, ‘Do this,’ and he does it.” When Jesus heard these things, he marveled at him, and turning to the crowd that followed him, said, “I tell you, not even in Israel have I found such faith.” And when those who had been sent returned to the house, they found the servant well.(Luke 7:8-10 ESV)
Have you ever heard the Donut man song about this? Catchy tune, but it leaves you thinking, what does this whole "I too am a man uncer authority" thing? It means the centurion got it - He understood that at Jesus' command things happen. It happened at creation; it happened when He was here on earth and healed or told someone they were forgiven; and it happens when we pray. That is true faith - believing in the Word.