1) System 2) System of rules 
• (a.) Of or pertaining to theology, or the science of God and of divine things; as, a theological treatise.
The`o·log'ic·al adjective [ Latin theologicus , Greek ...: confer French théologique .] Of or pertaining to theology, or the science of God and of divine things; as, a theological treatise. -- 
[adj] - of or relating to or concerning theology
theological About, using, engaged in, or typical of theology.
adjective of or relating to or concerning theology; `theological seminar`
relating to the study of the nature of God and religious belief