The most common and most likely answer to this crossword clue is the 7 plus 4 plus 5 plus 5 letter word WONDERS WILL NEVER CEASE
I've seen this crossword clue in The Times
W
O
N
D
E
R
S
W
I
L
L
N
E
V
E
R
C
E
A
S
E
Buddy explains!
The straight part
We know that "Good Lord/miracles are eternal!" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case good lord/miracles are eternal! = wonders will never cease.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.