Humanism is irrational

The humanist’s faith is based on his belief that nonrational causes cause rational beings (humans with minds) who are themselves composed entirely of the nonrational, and yet are somehow able to step outside of that nonrationality and reason to the conclusion that everything is material and therefore nonrational. Yet, if the nonrational material universe is “the whole show,” the humanist could never actually know if he is truly rational or only a nonrational material product with the illusion of rationality.

What is more reasonable to believe, that the nonrational produces the rational; or that a rational being (God) created other rational beings (humans) and a world founded on rational principles that can therefore be understood by these rational beings? The humanist must borrow from the theistic, Christian worldview, which can account for rationality. It is ironic that humanists often accuse Christians of possessing blind faith that the nonrational can produce the rational. Christianity gives birth to science, while humanism only gives birth to blindness.

Bob and Gretchen Passantino
Religion, Truth, and Value without God: Contemporary Atheism Speaks Out in Humanist Manifesto 2000 (Part Two)

The sacraments show God’s purpose for the physical world

Indeed, up to the present time, he has not disdained the water which the Creator made wherewith he washes his people; nor the oil with which he anoints them; nor that union of honey and milk wherewithal he gives them the nourishment of children; nor the bread by which he represents his own proper body, thus requiring in his very sacraments the “beggarly elements” of the Creator.

Tertullian
The Five Books Against Marcion, Book I
Chapter XIV

Creation is the evidence for God itself

Never shall God be hidden, never shall God be wanting. Always shall He be understood, always be heard, nay even seen, in whatsoever way He shall wish. God has for His witnesses this whole being of ours, and this universe wherein we dwell.  He is thus, because not unknown, proved to be both God and the only One, although another still tries hard to make out his claim.

Tertullian
The Five Books Against Marcion, Book I
Chapter X

God is the unbegotten maker of all things

It is not, therefore, for the name of god, for its sound or its written form, that I am claiming the supremacy in the Creator, but for the essence to which the name belongs; and when I find that essence alone is unbegotten and unmade—alone eternal, and the maker of all things—it is not to its name, but its state, not to its designation, but its condition, that I ascribe and appropriate the attribute of the supremacy.

Tertullian
Five Books Against Marcion, Book I
Chapter VII