Just listened to this sermon on the centurion's servant (found in Matthew 8:5-13). I also read Matthew Henry's notes on this passage and was struck by the following (emphasis added):
The servant got a cure of his disease, and the master got the approval of his faith. What was said to him, is said to all, Believe, and ye shall receive; only believe. See the power of Christ, and the power of faith. The healing of our souls is at once the effect and evidence of our interest in the blood of Christ.
And echoing Dr. Murray's closing prayer, "Help us to make sure we are children of the King."