I have seen some arguments for and against cross as of late.
Yes, Jesus did say "carry your cross and follow me". But he never literally told to use cross as a symbol, but that's what His followers chose as a symbol, after using the fish.
Those who shun the cross as the symbol remind that the cross was the device of torture and murder that was used to kill Jesus. While some people don't like the crucifix with Jesus figurine mounted on it, some don't want to use the device as a symbol altogether.
Others also dislike how wearing crosses has become a more of a fashion statement, which lessens it's meaning as a symbol of religion.
But tell me what you think of all this...
The use of the cross as a symbol is rather subversive. Because you're right, the cross was an instrument of torture and death--more than that, it was a symbol of terror, Rome used crucifixion as a public way to show the populace that they were in charge. Crucifixion was far more common in the frontier provinces, like Judea, as a means to keep the people in line through fear. The Romans reserved crucifixion for acts of treason, rebellion, and sedition; so having Jesus crucified was to treat Jesus not as a common criminal, but as a seditionist, that's why the charge mounted above him read, "King of the Jews".
But the use of the cross as a symbol demonstrates a subversive use of the cross; because Jesus' death on the cross is understood in a subversive way--in dying Jesus disarmed the powers and principalities, and rising from the dead demonstrated them ultimately powerless. Consider the language St. Paul uses throughout his letters in reference to the cross, such as, "
But far be it from me to boast except in the cross of our Lord Jesus Christ, by which the world has been crucified to me, and I to the world." (Galatians 6:14) Because Paul elsewhere has explained that God has chosen the weak and foolish things of this world to confound the wise, that the cross is foolishness to the world, but for us it is the very power of God to save. So from the very beginning the use of the cross was subversive, because of the One who died on it, and who in rising from the dead defeated every power and principality--for He has overcome sin, death, hell, the devil, and the world. He has deprived violence of its power, He has disarmed the rulers. So the cross becomes, for us, not the symbol of Roman terror and oppression, but the symbol of Christ's ultimate victory.
That's why we shouldn't be ashamed of the cross, but to place it front and center. And the symbol of the cross comes in many forms, the plain cross, the crucifix, and the Christus Rex
Because the cross isn't the symbol of our Lord's defeat, but of our Lord's victory. It is a sign and symbol of triumph, it signals the death of death, it signals the end of the devil's empire, it signals the destruction of sin, death, hell, and every power that stands to oppress God's creation which God, through His Son, is saving, is rescuing, and shall in the end make brand new, whole, and perfect.
-CryptoLutheran