I do not condemn for ignorance. That only means not knowing.
I am not comfortable with willful ignorance, the deliberate stopping of the ears and shutting of the eyes, and the incessant "I can't hear you! I'm not listening!" singsong.
Yet I believe in civil discourse. I will not challenge you, therefore to explain the Cepheids to me, but I will attempt to draw an analogy for you, so you will see why I am willing to trust the concept.
Imagine that you are standing at the rim of a large bowl-shaped valley, and that you can see houses on the other side, with white smoke rising from their chimneys.
You would conclude that if you actually walked over there, with your trusty Stanley tape of whatever length, that those houses would be a normal size, and not tiny little dollhouses.
Thus you can use what you see in a distant neighborhood as a measure of the scale of things in that neighborhood. That is the concept of the Cepheids: that they give us a way of reliably expanding our ability to measure things in a vast universe.
A universe so vast that light from distant suns takes billions of years to get to us. Regardless of the age of the Earth, the universe is more aged still. In fact, the stuff of which the Earth is made, all the metals and the oxygen and carbon, are leftover stuff from early massive stars that blew up, scattering material all over.
To me, this increase in scale does not diminish the awesome might and majesty of the Creator, it enhances it. The splendor of the night sky is a tapestry woven by a creative force of unimaginable magnitude, but my imagination gets a lot of stretching.