What dimension or dimensions do my guides and teachers reside in, and guide from? Please advise.

Your guides reside in multiple dimensions simultaneously. As guidance is needed, they step down their frequency as close as possible to the third dimension. It is not as complicated as you might think. As your vibration raises, your mind synchronizes to the guide’s vibration, enabling communication. You’re tuned in much like selecting a frequency on your radio.

How is it possible for an entity to be in multiple dimensions simultaneously?

The answer has to do with moving beyond the construct of time and space as it is understood in the third dimension. Once an entity moves beyond the third dimension, he or she is fully aware that everything is in the Now, and therefore, to put it in layman’s terms, there are no barriers between dimensions except for the ones you place upon yourself.