Often it is asked wether we should return to the moon first, and then launch to Mars from there. Often it is argumented that it would be energetically more efficient to launch from the Moon than from Earth. This is quite right - but only if all supplies originate from the moon. In the case of delivering supplies (e.g. food, water, propellant, hardware, etc.) from Earth to the Moon and from there on to Mars it isn't any more the best way for going to Mars. If you want to (or have to) make a stop in between, the best (at the moment accessible) point is the low Earth orbit (LEO). But why? The answer is easy: first: you have already to go to LEO when going to the Moon. Second (more important): it is easier to escape from LEO to Mars than from the Moon to Mars due to the difference in the gravitational potential at LEO and the Moon (the Moon lies deeper). So the question can't be: "Can we use the Moon as a waypoint for Mars?".

But what are the advantages of each of these goals? The Moon, of course is much easier to reach. Only about 3 days away, the risks of a mission to the Moon are much lower than on a mission to Mars. - But we have already been to the Moon. It's a dead piece of rock just orbiting the Earth. It's not at all that interesting than Mars. Mars has water on it - at least in the past in huge amounts. And where is water, there might be life - past or even present. But our Moon is a great resource - many kinds of valuable minerals can be found there - and even Helium-3 - the fuel needed for pollutionless and more effective fusion reactors. And the moon is a great location for astronomy, because it isn't polluted by Earth's light or even radio emissions (at least the far side off the Moon). But Mars is a great waypoint for missions farther out to our Solar System. You can create most needed resources there and use them to move outward.

You see, there are many arguments for both of them. And: they are independent from each other - so we will finally go to both of them - the Moon as a research base for astronomy and maybe (in the far future) for resource collection for Earth - and Mars as the most challenging target now considerable - with the possibility of finding life and ending the discussion whether we are alone in the universe. - No, we won't find higher life forms (esp. no intelligent life) on Mars, but when any kind of life has evolved there, it will also have evolved on extrasolar planets. And somewhere out there it would have had all the time to go through the evolutional states our ancestors have gone through...