KJV:
That their hearts might be comforted, being knit together in love, and unto all riches of the full assurance of understanding, to the acknowledgement of the mystery of God, and of the Father, and of Christ;
NASB:
that their hearts may be encouraged, having been knit together in love, and attaining to all the wealth that comes from the full assurance of understanding, resulting in a true knowledge of God's mystery, that is, Christ Himself,
KJV:
For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance; as ye know what manner of men we were among you for your sake.
NASB:
for our gospel did not come to you in word only, but also in power and in the Holy Spirit and with full conviction; just as you know what kind of men we proved to be among you for your sake.
KJV:
And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end:
NASB:
And we desire that each one of you show the same diligence so as to realize the full assurance of hope until the end,
KJV:
Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
NASB:
let us draw near with a sincere heart in full assurance of faith, having our hearts sprinkled clean from an evil conscience and our bodies washed with pure water.