Different Bible translations have slight word differences now and then.  One easy way to dig deeper into what the original Hebrew (old testament) and Greek (new testament) text has is to go to www.blueletterbible.org as follows:

First look up the passage in the King James Version and find the Strong's number for the word.

Next look up meaning of the number and study this in relation to the Bible text.

An example:  1 Corinthians 13:13  In the NKJV, NIV and NASB have "faith, hope and love" whereas the KJV and NAB have "faith, hope and charity".

I went to this link and typed in faith hope charity.  To find the passage noted with the Strong's numbers.  Notice how charity has the number 26 by it.

I then went to this link and typed in the number 26 then clicked Greek for new testament.

The search rendendered the word agape in the Strong's concordance.