Christian activism in the end times

If these are the end times, why should Christians pray and get involved in social issues? Many ministries like yours say that believers should be spreading the gospel, praying for solutions to problems like hunger and poverty, and working to shape our country's laws. I have serious problems with this. My study of the Bible and my understanding of "the signs of the times" convince me that this is the last generation and that Christ will be returning soon. If that's true, what good does it do to pray that things will get better? Couldn't we actually be opposing God's will by praying such prayers?