The first part of me lies at the entrance
Many pass over it without a thought
With only 3 letters it becomes everything
It never crosses the threshold but others go through it
The second part of me is a cereal
It may be found in the grocery store
Not many favor it, but a few enjoy
Others like it are not as dark
The third part of me is a favored item
It is coveted by many
It brings happiness, but no joy
It matches the hills and the trees alike
As a whole, couples seek me
I am the ultimate goal in a relationship
I am one of the united states
As a whole, I can be holy
Answer: Matrimony
