KJV:
Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall:
NASB:
Therefore, brethren, be all the more diligent to make certain about His calling and choosing you; for as long as you practice these things, you will never stumble;
KJV:
Wherefore I will not be negligent to put you always in remembrance of these things, though ye know them, and be established in the present truth.
NASB:
Therefore, I will always be ready to remind you of these things, even though you already know them, and have been established in the truth which is present with you.