Basics of Christian history in a colorful 2-page pdf -by Twenty-One Centuries .
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Diagram of Synoptic Relationships (David Pawson)
https://www.davidpawson.com/synopticrelationshipdiagram/Synoptic_Relationships.pdf
https://www.davidpawson.com/synopticrelationshipdiagram/Synoptic_Relationships.pdf