The Greek word translated as "cross" is stauros. It means the upright or stake portion of an instrument of execution that has been used in several cultures down through history. Sometimes executioners used a crosspiece at the top of or in different places on the stake; at other times, there was no crosspiece.
It's impossible to know exactly what type the Romans used in the crucifixion of Christ. It is clear, however, that the Romans attached a sign over His head (Matthew 27:37 Matthew 27:37And set up over his head his accusation written, THIS IS JESUS THE KING OF THE JEWS.
American King James Version×), which could have been upon a stake or a crosspiece. Because Christ's death is of such monumental significance to the Christian, some have mistakenly thought that the cross should be a part of Christian worship. But we should remember that it was an instrument of torture.
When we stop to realize that fact, it should be clear that it's grossly inappropriate to wear it as religious jewelry or an object of worship. Some would argue that using a cross in this manner symbolizes the value of Christ's death. We disagree. It's true that the apostle Paul referred to the cross in a symbolic way (1 Corinthians 1:17 1 Corinthians 1:17For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.
American King James Version×; 1 Corinthians 1:23 1 Corinthians 1:23But we preach Christ crucified, to the Jews a stumbling block, and to the Greeks foolishness;
American King James Version×). Paul also used the cup of wine from the Passover as a symbol (1 Corinthians 10:21 1 Corinthians 10:21You cannot drink the cup of the Lord, and the cup of devils: you cannot be partakers of the Lord's table, and of the table of devils.
American King James Version×). And John the Baptist referred to Christ as the "Lamb of God" (John 1:36 John 1:36And looking on Jesus as he walked, he said, Behold the Lamb of God!
American King James Version×). But this doesn't mean that we should begin to use cups or figures of lambs as religious ornaments or as objects of worship.
Furthermore, the second of God's Ten Commandments strictly prohibits the use of objects in worship. "You shall not make for yourself a carved image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them nor serve them" (Exodus 20:4-5 Exodus 20:4-5  You shall not make to you any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth.
 You shall not bow down yourself to them, nor serve them: for I the LORD your God am a jealous God, visiting the iniquity of the fathers on the children to the third and fourth generation of them that hate me;
American King James Version×). (For more information about how the Ten Commandments apply in everyday Christian life, please see the chapter "The Second Commandment: What is God Like" in the Bible study aid The Ten Commandments.)
God wants us to direct our worship and prayers to Him, not to any physical object. Christ explained this principle in John 4:24 John 4:24God is a Spirit: and they that worship him must worship him in spirit and in truth.
American King James Version×: "God is Spirit, and those who worship Him must worship in spirit and in truth."
Following the biblical instruction, the United Church of God does not use the figure or image of a cross in its worship services. Neither do members wear crosses as symbols of devotion. We refer to the cross in the way that the Scripture refers to it—that is, as a figure of speech to explain Christ's atoning death for us.