1 Cor 1:18
For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.
I think the cross is a quite appropriate symbol.
1Co 1:12 Now this I say, that every one of you saith: I indeed am of Paul; and I am of Apollo; and I of Cephas; and I of Christ.
1Co 1:13 Is Christ divided? Was Paul then crucified for you? Or were you baptized in the name of Paul?
1Co 1:14 I give God thanks, that I baptized none of you but Crispus and Caius:
1Co 1:15 Lest any should say that you were baptized in my name.
1Co 1:16 And I baptized also the household of Stephanus. Besides, I know not whether I baptized any other.
1Co 1:17 For Christ sent me not to baptize, but to preach the gospel: not in wisdom of speech, lest the cross of Christ should be made void.
1Co 1:18 For the word of the cross, to them indeed that perish, is foolishness: but to them that are saved, that is, to us, it is the power of God.
1Co 1:19 For it is written: I will destroy the wisdom of the wise: and the prudence of the prudent I will reject.
1Co 1:20 Where is the wise? Where is the scribe? Where is the disputer of this world? Hath not God made foolish the wisdom of this world?
1Co 1:21 For, seeing that in the wisdom of God, the world, by wisdom, knew not God, it pleased God, by the foolishness of our preaching, to save them that believe.
1Co 1:22 For both the Jews require signs: and the Greeks seek after wisdom.
1Co 1:23 But we preach Christ crucified: unto the Jews indeed a stumblingblock, and unto the Gentiles foolishness: