William Burkitt on 1 Corinthians 3:2

With milk, that is, with easy and common truths; not with the mysterious parts of gospel knowledge; with the first principles of the doctrine of Christ, and not with the higher doctrines of Christianity, which neither then nor now are ye able to bear.

Learn hence, That it is great prudence and wisdom in the ministers of Christ to instruct people in the first principles of religion, in order to their regularly advancing higher in Christianity. Ministers are spiritual nurses; they first must feed with milk, then with meat, otherwise they will not nourish, but destroy.