“Every thought we think is creating our future.”

Source: A Beginner's Guide to the Path of Ascension (The Ascension Series)

As rendered by T. Byrom (1993), Shambhala Publications.
There is no quote from the Pali Canon that matches up with any of these. The closest quote to this is in the Majjhima Nikaya 19:
"Whatever a monk keeps pursuing with his thinking & pondering, that becomes the inclination of his awareness. If a monk keeps pursuing thinking imbued with sensuality, abandoning thinking imbued with renunciation, his mind is bent by that thinking imbued with sensuality. If a monk keeps pursuing thinking imbued with ill will, abandoning thinking imbued with non-ill will, his mind is bent by that thinking imbued with ill will. If a monk keeps pursuing thinking imbued with harmfulness, abandoning thinking imbued with harmlessness, his mind is bent by that thinking imbued with harmfulness." Sources: http://www.accesstoinsight.org/tipitaka/mn/mn.019.than.html
Misattributed

Source: Heaven Revealed (Moody, 2011), p. 16

Source: The Key to Theosophy (1889)

Listen, Marxist!

Source: The Courage to Create (1975), Ch. 5 : The Delphic Oracle as Therapist, p. 99
Context: The self is made up, on its growing edge, of the models, forms, metaphors, myths, and all other kinds of psychic content which give it direction in its self-creation. This is a process that goes on continuously. As Kierkegaard well said, the self is only that which it is in the process of becoming. Despite the obvious determinism in human life — especially in the physical aspect of ones self in such simple things as color of eyes, height relative length of life, and so on — there is also, clearly, this element of self-directing, self-forming. Thinking and self-creating are inseparable. When we become aware of all the fantasies in which we see ourselves in the future, pilot ourselves this way or that, this becomes obvious.