Determining the relative age of a rock layer is based on the assumption that you know the ages of the rocks surrounding it.
The textbooks focus on relative dating, based on the layering of the rocks, and radiometric dating.
Relative ages are assigned to rocks based on the idea that rock layers lower in the strata were deposited before rock layers that are higher.
The Bible gives a much different picture and explains that relying on man’s reasoning is foolishness.
A fear of God and reverence for His Word is the beginning of wisdom.
Since relative dating can easily be verified by superposition (the younger bed over the older one), intrusion (the intrusive being younger than the intrusive rock), and use of index fossils (younger fossils in a rock layer make that layer younger than another containing older fossils), relative dating can be confirmed right at the field using one's direct observation.