From Easiest to Hardest

Idea
Money
People
Execution

Of course you need them all.

I talk to so many would be entrepreneurs that have this order confused. They think because they have an idea, they have some value.

Sure, better to start with a good idea than a bad one, but if you have the rest the original idea quickly changes.

The idea, without the rest, is rarely any sort of differentiator. An idea that has been built well, now that is something.