I am searching for scholarship, specifically in postgraduate theology study. How can I get it.

You will need to research specific opportunities at various seminaries. I don't know about theological post-grad work, but in many fields of study you can work as a TA for undergraduate courses in exchange for reduced tuition as you study towards your Masters Degree or PhD. Or you may be able to secure a grant for research into a particular topic for your dissertation - but again it will depend on where you do your study, and the contacts your advisor may have. So first figure out what institution(s) you are interested in attending, then contact them and ask.

Most scholarships at seminaries will come from the local church, from the demonimation and often though work study programs at the university