Conversation so far:
What is the major religion of Ukrainians?
A 2016 survey conducted by the Razumkov Centre found that majority of Ukrainian populations was adhering to Christianity (81.9%).
Do Ukrainians practice other religions as well?
As of 2016, 16.3% does not claim a religious affiliation, 1.7% adheres to other religions.
What do Orthodox Christians believe?
Eastern Orthodox theology is based on the Nicene-Constantinopolitan Creed. It maintains that it practices the original Christian faith, as passed down by holy tradition.
How are religious minorities in the Ukraine treated?
Ukraine's laws guarantee the right of religious freedom, and provide a legal framework for religious groups. Some groups have reported difficulties in legally acquiring property due to discriminatory treatment.

Question: What is the history of their religion?
Self-contained rewrite: What is the history of the Ukrainians' religion?