The Bible reveals the truth that “love never fails” in 1 Corinthians 13.
But, it doesn’t mean ‘any love’. The original word in Greek here is “Agape” (root word) for “Love” meaning “Love of God”.
Yup, it does “not” mean say, “Eros” (husband-wife love) which is “sexually based” that never fails (by itself, independent).
Now, an Eros relationship may only last if Agape was its foundation. For example, both husband-wife Eros love may last if Agape was their cornerstone.
A key characteristic to Agape being the foundation of an Eros type love is “same belief” (e.g. equally yoked in God evident by doctrinal equality) —> so any Eros which consists of at least one partner in ‘false teachings’ may cause that Eros to “end” or “continue in pain” (when forcefully held on to).
It’s better to be wise and end any such relationship immediately and be set free from its sins & errors if “before marriage”.
But if a couple is “already married” when they discover this, you have “no” choice but to learn to live together “in pain” due to this wrong choice unless the one with false beliefs repents restoring God’s Agape & Peace back into it unfailingly. Can you see it?
Remember, when an Eros type love ends, it ends both ways (so neither the man nor the woman have proved their Eros to “never fail”) —> only “Agape never fails” or “never ends”.