The objection argues that if knowledge, power, and life are eternal, several eternal realities appear to exist, perhaps threatening divine unity. The hidden premise is that every eternal attribute must be an independently necessary being.
The response distinguishes an attribute's beginninglessness from the independent subsistence of an essence. An attribute may be eternal while remaining an attribute of the one God, not an additional self-subsisting deity.
Thus 'knowledge is eternal' does not imply that knowledge is a second god entitled to worship. The feared plurality follows only by reifying attributes into independently existent essences.