In that book, Wattles shared his keen insights into manifesting riches (or anything else, for that matter) in such a powerful way that nearly 100 years later, his book is still a favorite of millions of readers the world over.

Following are 3 powerful lessons Wallace Wattles revealed in one of the most studied success books of all time.

1. We live in a thought world. As such, we're part of a thought universe. Therefore, whatever you think about consistently expands and tends to materialize in your life. This means that your thoughts have the power to shape your life and create your reality in detail.

Everything around you originated in the form of a thought. What began as a simple thought manifested into the chair you're sitting, the computer you're using, the paint on the walls -- everything. It all started in thought substance. Thought is the only power that can produce tangible results.

Think it first and visualize it as your reality. According to Wattles, that's exactly how you create things in your life. Since you have the power to choose your thoughts, you can create or manifest what you sincerely want and earnestly desire.

In Wallace Wattles' own words, "If a person can communicate his thought to original thinking substance, he can cause the creation or formation of the thing he thinks about."

2. Hold on to the thoughts you want to manifest. To attain any goal or desire, you must stay focussed. Focus is the great secret. For many people, staying focused on one objective until they reach it is difficult.

But Wattles advises to continue thinking about what you want and accept it as your reality. We must learn to "Think truth regardless of appearances." No easy task, to be sure. But to the determined soul, this could be the key that unlocks the door to their most cherished dream.

Once you've decided on a result you want, claim it as yours. Maintain an unquestioning faith that whatever you want is actually on the way. You've placed your order with the universe and your continued and persistent thought on the reality of the result is certain to bring it about.

Know what you want and want it enough that it's easy to keep this desire in your thoughts. Wattles suggests that we should ignore present conditions and circumstances as these are nothing more than the manifestations of past thoughts.

3. The third life lesson is to simply be grateful for it all. Gratitude, sincere gratitude connects you to your unlimited power. Call it God, Spirit, Infinite Intelligence, the Divine - whatever you choose. It's this connection that facilitates the manifestation of all things. Gratitude raises your vibration. As long as you're feeling appreciative, you cannot be angry, frustrated, disappointed, or sad.

Be grateful for every result, not just the grand and glorious. This may be a difficult idea to adopt. But it's one that can help but serve you well if you listen to the advice of Wallace Wattles.

In the author's own words, "All things have contributed to your advancement; therefore include all things in your gratitude." In other words, you are the product of your past experiences and circumstances. All those things are history but each has contributed to the person you are today. Be grateful for it all and keep thinking about what you want.

There you have it -- 3 valuable, even life-changing lessons from the early 20th century sage, Wallace Wattles. Read them again. Absorb these truths and then think and visualize your ideal future result.