Wow, has anyone else thought of doing this?
It seems like a great way to protect Moses from being discarded (e.g. Angel of the Lord), while still using his negating abilities.
I assume you meant Christian Martyr instead of Angel of the Lord?
At any rate, including 1 card just to protect 1 hero in territory is usually not a good strategy for Type 1 decks. If your deck is 50-57 cards (which most are), after accounting for lost souls and Dominants, you only have 35-42 slots for your offense, defense, and support cards. Goshen just isn't worth it at that point.
And frankly, if your opponent resorts to playing Christian Martyr on your Moses in territory instead of using it to block a rescue attempt, you are already ahead. Not to mention that Angel With the Secret Name, Angel Under the Oak, and Eternal Covenant are all really good cards that work well in decks with Moses, and all can get him back from discard.