Most of us have been around someone who's negative attitude can drain the joy right out of the room.
The question is, “ how do you react to their attitude”? Do you allow them to pull you into their pit, or do you stand firm in Godly behavior and your knowledge as a Christian? If we put on our full Armour of God daily, we will be able to stand in the love and forgiveness that God has shown for us. We need to be a reflection of him and show the world through us;
2 Corinthians 2:7 (KJV) So that contrariwise ye ought rather to forgive him, and comfort him, lest perhaps such a one should be swallowed up with overmuch sorrow.