Sach collaborated with Nigel Beynon to produce a book on how to understand the message of the Bible. Dig Deeper, was published by IVP in 2005. He has recently completed Pierced for Our Transgressions with Dr Steve Jeffery and Dr Mike Ovey of Oak Hill, in which they defend an orthodox understanding of Christ's crucifixion as penal substitution.
Dig Deeper: Tools to Unearth the Bible's Treasure (IVP, 2005) (co-authored with Nigel Beynon)
Pierced for Our Transgressions (IVP, 2007) (co-authored with Dr Steve Jeffery and Dr Mike Ovey)