KJV:
That thou mightest know the certainty of those things, wherein thou hast been instructed.
NASB:
so that you may know the exact truth about the things you have been taught.
KJV:
Saying, The prison truly found we shut with all safety, and the keepers standing without before the doors: but when we had opened, we found no man within.
NASB:
saying, "We found the prison house locked quite securely and the guards standing at the doors; but when we had opened up, we found no one inside."
KJV:
For when they shall say, Peace and safety; then sudden destruction cometh upon them, as travail upon a woman with child; and they shall not escape.
NASB:
While they are saying, "Peace and safety!" then destruction will come upon them suddenly like labor pains upon a woman with child, and they will not escape.