Circumcision and the sacraments show precepts may lack intrinsic light; God's authority is the chief ground

When the Israelites in Egypt were taught that every male was to be circumcised on the eighth day, that they were to abstain from blood, that some animals might be eaten and others not, and more of that kind, no one can deny those things were to be embraced by them with faith, as things pleasing and acceptable to God. Yet who could sincerely and from the heart say those things had in themselves a light enough to make faith, and enough to compel believers' minds to conclude that God had commanded and handed them down? The same can be said of us today about that washing of water used in Baptism, and about taking bread and wine at the Lord's table.

So when many dogmas and precepts must be taken up by faith, though they do not have in themselves the light and evidence by which they would prove themselves with enough certainty true and handed down by God, it is clear that the principal ground and basis of the faith by which we take up what God's Word delivers and religion's dogmas is not the thing's own truth and evidence, but rather the truth and authority of God teaching and revealing.