The phrase "powerful intellect" refers to someone who has a very smart and strong mind. They are highly intelligent and able to think deeply and solve complex problems. Full definition
Clearly, there is no shortage of powerful intellects in any culture. (faith.org.uk)
I mean, at best he is calling God a liar by knowing something God says can not be known, and at worst says that God didn't have the power to keep it unknown from his (Camping) more powerful intellect. (religion.blogs.cnn.com)
The rudiments of the consequent Christian philosophy, theology, and art were already in place by the late third century: Christians could boast of Origen, for instance, a powerful intellect by any standard. (firstthings.com)