The Lord looked and was displeased
    that there was no justice.
He saw that there was no one,
    he was appalled that there was no one to intervene;
so his own arm achieved salvation for him,
    and his own righteousness sustained him.

~ Isaiah

All of us experience pain.  We cry out at injustice and we hope that someone acts.  God sees every misfortune and he will not let a single one go without justice.  More importantly, God will save the one who is the victim of injustice.

The truth is that we create injustice.  Many times we do not think about it, though perhaps in this day and age, we are more aware.  Are we shopping locally?  Are we buying fair trade?  Do you think green?  Living without causing harm is difficult and perhaps even impossible in this broken world. 

Do you stop trying?  -- No.  This is too important to ignore.

Do you consider your efforts good enough? -- No.  We are responsible for causing other people pain.  To the best of our ability, we should work in earnest to reduce human suffering.

Do we succeed?  Never, the problems are too big and too systemic.  This is something that goes deeper that even our communities can solve working together.

If we all try and yet all fail, then what hope do we have?  No one succeeds and we all lose.  On one extreme, someone might say "no one have any more kids, humans are evil".  On the other extreme, someone might say, "we might as well not even try."  However, God says, "I see, and I will save."

Let God be God!  Take the pressure off your shoulders to save humanity.  Engage like God engages, but engage because you are becoming more like Jesus in following Him.  Live a life empowered by the Holy Spirit, letting Him do the heavy lifting.  In this way, you work hard without a burden.  You work with joy and injustice is squashed.