The word "understanding" is a key word in this portion of Scripture. James used a word here that is used exclusively in this text and it connotes a "specialist". It takes a "specialist" to receive and properly apply wisdom. How would you like to be known as someone who specializes in wisdom? Could you live with that?
How do you know when someone is a wisdom specialist? Do they have a business card? Do they get a title? If you want to pick them out of a crowd what would you look for?
That is essentially the point of this portion of Scripture. A practioner of wisdom demonstrates a very distinct lifestyle. He has attitudes and actions that set him apart from those who do not understand true wisdom.
So, wisdom is intensely practical. It is not just subscribing to a particular set of beliefs or creeds. Wisdom is not a matter of what you know but what you show. Knowledge is important and you certainly must know the correct things. But simply having head knowledge doesn't guarantee a change of heart or behavior. The world is filled with highly educated and very knowledgable people who live ungodly lives because knowledge tends to puff up a person with pride. Pride and wisdom are mutually exclusive.
Show me a wise person and I will show you a humble person. The wise person understands that knowledge brings power and he respects that power. Wise people understand that there is a responsibility that comes with knowledge. Humble people live under accountability to the power and the responsibility of knowledge.
The wisest man who ever lived summed up the wisdom, knowledge and understanding interface this way, "Trust in the Lord with all your heart and lean not to your own understanding. In all your ways acknowledge Him and He will dirct your paths." Proverbs 3:5-6
Do you need to "wise up"? Are you trusting in what you know or are you living out what you believe? Has your knowlege puffed you up with pride or has it humbled you? Do you seek to use your knowledge as leverage to promote yourself at the expense of others?
The truth remains, if you really believe it your life will show it.