Well to be accurate, actually he was part of a plot to murder Hitler. A bit different than the quite benign ‘resisting Hitler’ bit above. I.e., he wasn’t an innocent martyr but a man taking part in a plan to commit murder. That goal right or wrong, it’s nonetheless quite inappropriate for Christians to plan murders.
Bible Gateway has whitewashed Bonhoeffer. That may sell in middle America among the unlearned and ignorant readers of Eric Metaxas, but it won’t work historically.