If we want to know whether there is life beyond Earth then the quickest way to answer that question is to explore Mars. That exploration is currently being done by remote space probes sent from Earth.
The race is on though to send human explorers to Mars and a number of Earth-bound projects are trying to learn what life would be like on the red planet.
The first suggestion is pointless and unethical – we would be sending astronauts to their certain death – while the second would be a licence for us to continue polluting our home planet.
I believe we should go to Mars because of what we can learn from the red planet, and from developing the technologies to get people there safely.