Just as Paul’s readers would have been familiar with the Roman military machine and the armor worn by the Roman soldier, they would have been familiar with Roman military formations. The imagery of the testudo, or tortoise formation held a strong message for the churches of Paul’s day and today as well.
The tortoise was formed when a command was given on the battlefield and certain of the soldiers began to create the perimeter of a square. Immediately other soldiers filled the center, and the final perimeter was drawn, so that in seconds, a square mass of soldiers had been formed. The soldiers of the perimeter quickly locked their shields together, creating an impenetrable wall around them all. The soldiers inside the perimeter raised their shields above their heads and locked them as well, effectively creating the semblance of a tortoise who had withdrawn its head into its shell.
One soldier was commissioned to be the eyes of the testudo, shouting out orders so that each soldier, even the one in total darkness at the very center of the square, could hear that one voice and know where and how to step so that the entire mass could continue to move forward in an absolutely impenetrable formation. [note: some fabulous Zion implications here!]
What a tremendous picture Paul has painted for the Ephesian church! He has challenged each believer with their individual responsibility to understand the enemy, anticipate the battle, and know his own armor well. He has used powerful imagery to help each one understand how to use that armor, perhaps even to symbolically put it on every day, being reminded of the power God has given each believer to be victorious in every situation.
But a single soldier cannot hold out very long. Paul’s readers were well aware of the disciplined fighting force the Romans represented and his use of such imagery admonished them to take their positions as part of just such an army. As much as each one would protect himself, he must be willing to fight with and for his brother: “praying always with all prayer and supplication in the Spirit, being watchful to this end with all perseverance and supplication for all the saints” (v. 18). Each one should be willing and practiced to be a part of that tortoise, shields locked with those around him, surrounded by a solid wall of unshakable faithfulness, listening only to the voice of the Lord, and moving forward at His command.
All of the references and wonderful illustrations for this article can be found at