I am convinced that the greatest singular act of personal worship that you can render the Lord is to have a thankful heart. I believe that the Lord desires for us to worship Him with the fruit of our lips as we receive blessing after blessing. When we are thankful, it ultimately crucifies self-interest and motivations. Being thankful helps us recognize God for who He really is, as the source of everything. Thanksgiving is always able to reach God in the midst of difficult circumstances. God is to praised, and sees beyond the pain to the plan for now. If you are a thankless person, you have missed the point because the whole of our Christian life is to finally come to the place of thanksgiving.