Remembering without ceasing your work of faith, and labour of love, I Thes. 1:3. Clearly, the Apostle Paul saw work and labor as two separate things. One of the marvels of the King James Bible is the exact precision with which it states doctrine and narrative. To a Jew such as Paul, there was an important distinction between the two. Work is one thing, labor is another. Under the old covenant, the Lord had forbid work on the sabbath, not labor.
A couple of years ago, a religious Jew from Israel was visiting with us at the Black Creek Baptist Church. He is a man fascinated by King James Bible believing Christians. Even within Israel, he is accounted as an expert in Biblical Hebrew as well as many other languages. Even though he is not a Christian, and even though he does not believe the New Testament, he is a fan of the King James Bible. He has publicly marveled over the exactness of its translation.
He gave a talk to my people on using the construction of the tabernacle to distinguish work from labor. He explained how that his Hebrew Bible, which he has read from his youth, makes a very clear distinction between work and labor using two distinctly different words. He showed us how that the King James Bible carried that over by translating one of those words as "work" and the other as "labor" and never intermixing the two.
Work is the process by which things are created or changed. Labor is the effort to maintain those same things without altering them. In his talk, to which I have provided a link at the bottom of this post, he explained how that anything that had to be created in the tabernacle was an example of work. The effort necessary to maintain those same things was not work, and was not forbidden under the Old Testament sabbath. A man could not make a candle stick on the Sabbath, but he could dust it. A man could not print a book on the sabbath, but he could read it, or put it back on a shelf.
In I Thessalonians 1:3, we see that Paul also saw a distinction between those two words. Remembering without ceasing your work of faith, and labour of love; we see that men create and build new things by faith, but they maintain and upkeep them through love. Men establish churches by their faith in the written Word of God. That is their work. Others labor in that vineyard motivated by love. A child of God does the work of God through his faith in what God has instructed him to do. Another labors over that work to maintain it and keep it fresh.
A King James Bible believer never needs Greek or Hebrew lexicons to understand his Bible. The words are exact words.