Dietrich Bonhoeffer‘s involvement with Abwehr caused him…

…to forgo his previous position of outward opposition to the regime and suddenly pretend to be in step with it. But of course it was only so that he could be in opposition to it on another, more fundamental level.

This involved deception!

(Bonhoeffer: Pastor, Martyr, Prophet, Spy by Eric Metaxas, 365).