Teaching materials using spiritual concepts learned in classes I paid for. Do I have to include the copyright lineage?

Question

My teaching materials are my original ideas & design using concepts from a research group who shared them freely.  My former partner is angry that I took his name & company name off my materials when we broke up. I re-named everything I created and credited him where he actually made a contribution, on only 3 of 26 pages.  Is it ok  to change my copyright from his name along with mine )co-teaching, to just my new company name and technical healing process.  It is metaphysical teaching of a healing technique.  He did not help with the process or design at all, he simply taught me the concepts and I paid big $ for that training.  From there, I created brilliance and now that we split, he wants me to put it all back in our joint name & his company name.  I did not legally copyright.  Just used the symbol & sent it to myself with the postal proof of date, return address.  The material from the research group was copyrighted in the same manner, never formally done. Thank you for your help.

Will Blackton · Answer

Creative works receive copyright protection from the moment they are fixed in a tangible medium of expression.  "Sending yourself materials through the mail to get copyright protection" is a myth that does not affect your copyright protection at all.  Creative works receive more robust protections if they are registered with the U.S. Copyright Office.  If you're not registering these works with the U.S. Copyright Office ("I did not legally copyright"), I'm unsure of what you mean by "change my copyright from his name along with mine )co-teaching, to just my new company name." 
 
Although using copyrighted materials for educational purposes may qualify as fair use, if your teaching is a commercial enterprise and not organized as a non-profit, that certainly undercuts a fair use argument.  If you're going to resell these materials or use them in connection with a teaching business, you need to consult with an attorney to effectively protect your interests.  An attorney can help you negotiate obtaining the intellectual property assets you want to use, advise you on how to avoid potential infringement claims in the future, as well as help you protect your own works from unauthorized reuse. 
 
So, to answer your question directly: reusing someone's creative works without their permission is generally copyright infringement, crediting the creator does not relieve you of this liability.  Whether you were a coauthor of these materials will have an effect on a potential infringement claim, but there aren't enough details in your post to say what that effect would be.

Q: Teaching materials using spiritual concepts learned in classes I paid for. Do I have to include the copyright lineage?