‘And He said to them, “Go into all the world and preach the gospel to every creature.  He who believes and is baptized will be saved; but he who does not believe will be condemned...” (Mark 16:15-16)’.
Jesus is telling his disciples to get into action.  They are to, ‘Go’.  As His disciples, we also are to get into action - men and women getting out the Word of God to a needy world.  By the way, Jesus is not saying here that that if you are not baptized you will be condemned, but rather that the person who is, ‘saved’ will be baptized.  It is the rejection of Jesus Christ which brings eternal condemnation - “He who believes in the Son has everlasting life; and he who does not believe the Son shall not see life, but the wrath of God abides on him” (John 3:36).
So hear we see a direct call into action.  It’s a strange world we live in isn’t it - in Mark we see a call to go into all the world and preach the gospel to every creature; it’s a command from the King, and yet so few people really get this.  
We live in a world today which responds to every good cause and need as it arises.  Individuals and nations will dig deep into their pockets to fund these good works.  It is wholly right to help those in need, but the irony is that so few will, ‘dig deep’ to see the gospel preached to every creature.  There is something about, ‘good works’ that attracts us and if we are honest, makes us feel better when we respond to the earthquake, the tsunami, flooding, famine etc.  
But should we not be looking at the multi-millions that are going to hell without Christ as well as feeding the poor and looking after the disadvantaged?