The use of "the" article

Leave the second "the" in to show specific sections of the bible.

Nat, good q

The speedreader responds, I came to a halt when I expected that first'n to conclude, '...,and the....'

Nat was tht'n too deep
....but'd be most happy to elab

The choice of sentences is very poor. There are a great many differences between the Old and New Testaments. They are completely different in every respect. It's a bit like like saying there is a difference between "A Brief History of Time" and "Bridget Jones' Diary". Sure there is.

Ignoring the foolishness in the example sentences:

Use one 'the' but make Testaments plural, then these sentences mean the same:

1. There is a difference between the Old and New Testaments.
2. There is a difference between the Old and the New Testament.

Thank you for clarifying that.