What is the "immaterial tabernacle" which Jekyll looked to change? For what reasons?

The quote goes like,

"for any drug that so potently controlled and shook the very fortress of identity, might, by the least scruple of an overdose or at the least inopportunity in the moment of exhibition, utterly blot out that immaterial tabernacle which I looked to it to change."

Jekyll is willing to use his body as a lab rat to reach the euphoria of being totally bad.