What has man invented that has an immune system? What can man build that can fight off a microscopic attack and heal itself? I think of the many simple or mechanical or electronic devices I have had. When they broke they remained broken until and unless someone fixed them. No such thing as healing. (Sometimes if you whacked something just right it would work again for a while - but even that whack was an outside intervention.)
So, we have this amazing immune system! And, ironically, some people point to the flexibility of the immune system as an evidence that the system came to exist by chance. "See how it adapts through mutation? This proves evolution as the source of life!" For them, the complexity is wonderful - but they worship the creature itself rather than the Divine Creator.
No! Don't be so blind and foolish! See what is right before your eyes!
(Psalms 139:14) I will praise You, for I am fearfully and wonderfully made; Marvelous are Your works, And that my soul knows very well.