In what dictionary does “profitable” mean “necessary” or “sufficient”?
Doesn’t the Bible contain more than enough to deal with already?
Scripture gives me more than enough to keep me busy, for a lifetime.
Why do Catholics need or want to add more to Scripture?
Why would you want to do that to yourselves?
If you are seeking a bit more clarity you can go here:
http://www.blueletterbible.org/lang/lexicon/lexicon.cfm?Strongs=G5624&t=KJV
If you browse around that site for the specific word you can also see the passage in Latin and Greek.
We can be sure the context here is not profit as in material wealth, but in godliness.