Do you rejoice in the Lord all day long? If so, you most certainly must be praying without ceasing. If this describes you then you should also be giving thanks for all that the Lord provides, and does, for you as your day proceeds. All three of these things, Rejoicing, Praying, and Giving Thanks, are all contained in a single sentence as Paul writes to the Thessalonians. They are joined for a reason, and are meant to lift us up in spirit... then join with the words Always, Without Ceasing, and All Circumstances, to show us the degree of their importance.