Yes, there are people out there who will harm you the first chance they get for their personal gain,yes there are people out there who will use you for their own benefit. There are bad people out there, nasty, cruel people. And they are probably a majority if you are living in a corrupted society.
But always remember, these people were not always like that. They too were people with kind hearts, people who later learned that negative opportunism was the way of life. Who learned that this twisted thinking is the standard way of life.
And you need to realize that we cannot go on like this. We need to change and it needs to start from within us. So go out there and smile where others frown, help where others ignore, do where others avoid, give where others take, speak kindness where others shout and abuse, be honest where others cheat.
So that when people experience you, witness you encounter you, they go back home that day remembering a person. A person who was different, a person who stood out, a person who went against the cruel society norms, a person who fills their hearts with newfound hope, a person who reminds them of themselves before they were exposed to this world. And this is where you triumph, for when you have inspired one being, you have inspired the whole of humanity.