Russell believed it was very important that all Christians, including those who were attending churches, should learn those "truths". He believed these "truths" had been hidden in the Bible for thousands of years. He started a publishing company called the Watch Tower Bible and Tract Society of Pennsylvania. He wrote several books, set up Bible study classes for people to study his teachings, and started a magazine, "Zion's Watch Tower and Herald of Christ's Presence", which taught that Christ was already present.