Many of the British Iron Age Coins were buried in large caches near temples. That brings up a question as to which deity they were offered. The coins were apparently votive offerings.
Here is where it gets questionable. While many of us believe in God, and we would not accept the gods of the British Iron Age, perhaps we should have a deep reasoning here.
God is the omnipotent Being who created us. His nature has many aspects, and we accept Him as the combination of all of those aspects.
So, in antiquity people often sought a supreme Being to worship. In some cultures, there is a chief deity and other deities for certain gifts that the true God bestows. In that light if a culture realized the benefits for life from the sun and worshipped the sun, would God accept the worship as directed at Him as best understood by that culture? Understand, it is not us judging the merit of how a people understood God, it is God’s understanding that is important. So, if the Iron Age tribal people of Britain intended to worship God the Creator, even though they erred in understanding, is it possible that God accepted sacrifices offered. Realize these people offered quite large treasures, and even weapons, so it is likely they were attempting to make offerings to God the Creator as understood by them.
After contemplating the last paragraph, we must ask if the true God accepted the votive offerings, and if so, would it be sacrilege to remove and own them? Thus, we have a moral dilemma. Part of the problem is that we do not know what the intent really was by the person burying a given hoard.
Of course, if worship of a false god is obvious and done for personal gain, such as a Roman general agreeing a Caesar were god for political gain, there would be no question. The artifacts would have been given not to God, but to Caesar, with no real intent to serve the true God.
The size of a typical hoard of coins and other artifacts indicates there probably was sincerity by the person making the offering. Hence, the moral problem arises.