Rail

It's not words that forgive, it's the heart that forgives
It's not words that apologize, it's the heart that apologizes
It's not words that give respect, it's the heart that gives respect
It's not words that accept, it's the heart that accepts
Rhetoric is not necessary, it's the heart that's necessary

Words.
Perhaps words are like railway tracks.
No matter how close a heart and another heart are, they're a great deal further apart
Railway tracks become important to connect both hearts, and so it seems words were born for this reason
That rail exists, and people can go freely back and forth to each others' hearts
If that's the case, then a song seems to be a train decorated in armor for a fascinating SHOW

The railway tracks will occasionally transport sadness until insincerity

Even though words can say goodbye, the heart is there without saying goodbye