Do you remember the widow in the Bible who only had two very small coins to give to God's work? In the eyes of most people her gift was useless -- but Jesus commended her to His disciples: "This poor widow has put in more than all the others" (Luke 21:3).
Why did Jesus say this? One reason was because in God's eyes it wasn't the size of her gift that mattered, but her attitude of sacrifice and love for God. In addition, Jesus knew that God could take even the smallest gift and use it for His glory. And the same is true for us. If Christ is first in our lives, our desire will be to support His work in every way we possibly can. Is this your goal?
Ask God to guide you in your giving. No, you can't support every cause that comes your way -- nor should you try. But you can seek God's will for your giving, asking Him to direct you to give to those that need it most. Pray too for those organizations, that God will help them use their resources wisely and carefully.
Above all, seek to follow the Bible's teaching in your giving: "Each man should give what he has decided in his heart to give, not reluctantly or under compulsion, for God loves a cheerful giver" (2 Corinthians 9:7). May this be true for you -- and it will be, as you put Christ first in your life.