Suicide bombing by Hamas

Here is an article about a suicide bombing in Gaza acted out by Hamas. Hamas said that it was a step forward for those who are awaiting freedom. Hamas is attacking entry points in an attempt to start a humanitarian crisis that will force international actors to put pressure on Israel.

From what I understand, Hamas is claiming that their purpose is to help the Palestinian people regain their land. If this is their goal, then why are they killing those that bring aid into areas that contain Palestinian people? Even if it forces international actors to step in, is the cost in lives equal to the benefit? Will this have any effect on how much support Hamas later gains?