Holy?

I grew up in a Christian society that drew a thin invisible line that separated us from our ancestors, their form of worship and labelled them ungodly. Our ancestors offered their supplications unto God through Spirit Mediums by way of ancestral lineage, if the goal was to reach Musikavanhu what then was the assumption of the unholiness of the spirit that possess the medium based on? Is it possible for that which is unholy to have an understanding of God and forge a relationship with him? In one of His songs Oliver Mutukudzi said Midzimu yedu yaiziva Mwari vakomana (Our ancestors knew or had a relationship with God). He went on to imply that any thoughts contrary is an offence not only to the ancestors but to God as well. These are the words that inspired the Holy? Portrait of Mbuya Nehanda, was she by any means Holy? Is the question that the art work is meant to involve in people`s minds and whatever conclusion one comes to  will determine whether they will build or burn the bridge that connects us not only to Mbuya Nehanda but our ancestors in general