[seclorum]

The point is not: how. The point is: why.

[Peaker]

There are plenty of resources on why you would want to program functionally.

One of the most notable one is:

http://www.cs.utexas.edu/~shmat/courses/cs345/whyfp.pdf

Benefits include: Easier reasoning about code correctness. More powerful abstractions leading to clearer and more succint code. Easier mechanical refactoring of code. Easier parallelism. More powerful compiler optimizations.

[seclorum]

Great, now answer: why not.

[eru]

Depends on what you are looking for.

Apart from any benefit from actually using any language or tool, there's also the joy of learning.