Romans 10:2

Romans 10:2. For I bear them record that they have a zeal of God, but not according to knowledge.

We should always give people credit for every good thing that there is in them: it will often enable us all the better to point out other matters in which they are deficient. So Paul put it on record, concerning the Jews of his time, that they had a zeal for God, though it was not a zeal "according to knowledge."