Now let's examine these two....also related questions.
"Should images be used in worship?"
Since the Jews were forbidden to use images of "anything" in their worship, the Christians would have followed that law because, according to scripture, idolatry was one of God's pet hates. (Exodus 20:4-5; 1 Corinthians 10:14) When the unfaithful Israelites fell to worshipping a golden calf after their miraculous liberation from Egypt, God punished the culprits with death. They called that image "Jehovah" (YHWH) and supposedly held a festival in his honor, with singing and dancing....but it was disgusting in God's eyes.
Later when Israel fell to worshipping Molech and began to sacrifice their children to this false god, he punished them again and cleared out all of their disgusting idols. (Leviticus 20:2; Jeremiah 32:35) Idolatry seems to be a magnet for religious people because they want a god they can see. Jehovah will never be that God. He requires his worshippers to
"walk by faith, not by sight". (2 Corinthians 5:7)
"Was the cross a religious symbol for Christians before Catholicism introduced it?"
Since God's worshippers were forbidden to "make images" to be used in worship, the cross is also an image and therefore not acceptable as a symbol of the death of Christ....not only because there is no mention of a cross in the Bible, but also because veneration of the cross pre-dates Christianity as a religious symbol, by centuries. It has very grubby origins.
The Greek word rendered “cross” in many modern Bible versions is
stau·rosʹ. In classical Greek, this word meant merely "an upright stake, or paling". Later it also came to be used for an execution stake having a crosspiece....but no crosspiece was ever mentioned in the scriptures.
The Bible also uses the word
xyʹlon to identify the device used to put Christ to death (Acts 5:30).
A Greek-English Lexicon, by Liddell and Scott, defines this as meaning:
“Wood cut and ready for use, firewood, timber, etc. . . . piece of wood, log, beam, post . . . cudgel, club . . . stake on which criminals were impaled . . . of live wood, tree.” It is translated "tree" in most Bibles.
...and this is in agreement with the apostle Paul's words at Galatians 3:13...
"Christ redeemed us from the curse of the law, having become a curse for us—for it is written, “Cursed be every one who hangs on a tree”......it was written in God's law.
Mons Perret, who spent fourteen years doing research in the catacombs of Rome, counted in all a total of 11,000 inscriptions among the millions of tombs. According to him, “not until the latter years of the fourth century does the sign of the cross appear.” (About the same time as Roman Catholicism was declared the state religion. It was Constantine who brought the cross into the Roman "church") Among the signs that do appear are the dove, a symbol of the holy spirit; the lyre, a symbol of joy; the anchor, a symbol of hope and the fish....none of which were venerated.
"A vast body of evidence shows that the cross was used centuries before the birth of Christianity. The cross is thought to have originated from the ancient Babylonians before its spread to other parts of the world such as Syria, Egypt, Greek, Latin, India, and Mexico. The pre-Christian cross was used as a religious symbol and as an ornament among the Egyptians, Syrians, Greeks, Persians, Europeans, and in some parts of Africa. There was, therefore, universal use of the pre-Christian cross.
The Christian cross as a Christian symbol has its roots in ancient paganism. The use of the Christian cross as a Christian symbol began after the time of the Constantine, which occurred three centuries after the coming of Christ. The crucifixion and death of Jesus on the cross conferred a new significance to the use of the cross in Christianity. Before the death of Jesus on the cross, the cross was used privately among Christians. Its purpose was restricted. After the Constantine, the use of the cross was acknowledged as a symbol of Christianity."
The History of the Christian Cross
In the book of Ezekiel, apostate Israelite women are seen "weeping over the god Tammuz" (Ezekiel 8:14)
Among the Babylonians an upright cross was a sacred symbol. As in the Hebrew alphabet, such a cross was the original form of their letter T (or
Taw), and so it was the initial letter of the name of their god Tammuz. The cross was worshiped centuries before the so-called Christian era.