And he that takes not his cross, and followeth after me, is not worthy of me. Matthew 10:38

Then said Jesus unto his disciples, If any man will come after me, let him deny himself, and take up his cross, and follow me. Matthew 16:24

For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God. 1 Cor. 1:18

But God forbid that I should glory, save in the cross of our Lord Jesus Christ, by whom the world is crucified unto me, and I unto the world. Gal. 6:14

My spirit is made an offscouring for the Cross, which is a stumbling-block to them that are unbelievers, but to us salvation and life eternal. ”Where is the wise? Where is the disputer?”Where is the boasting of them that are called prudent? Ignatius: to the Ephesians (A.D. 35-105) ch.18

(Addressed to the Jews) And you yourselves, if you will confess the truth, must acknowledge that we, who have been called by God through the despised and shameful mystery of the cross (for the confession of which, and obedience to which, and for our piety, punishments even to death have been inflicted on us by demons, and by the host of the devil, through the aid ministered to them by you), and endure all torments rather than deny Christ even by word, through whom we are called to the salvation prepared beforehand by the Father, are more faithful to God than you. Justin Martyr (A.D. 150) Ante-Nicene Fathers vol.1 pg. 265

For that He did not say this with reference to the acknowledging of the (cross) above, as some among them venture to expound, but with respect to the suffering which He should Himself undergo, and that His disciples should endure, He implies when He says, “For whosoever will save his life, shall lose it; and whosoever will lose, shall find it. And that His disciples must suffer for His sake, He [implied when He] said to the Jews, “Behold, I send you prophets, and wise men, and scribes: and some of them you shall kill and crucify.” And to the disciples He was wont to say, “And you shall stand before governors and kings for My sake; and they shall scourge some of you, and slay you, and persecute you from city to city.” He knew, therefore, both those who should suffer persecution, and He knew those who should have to be scourged and slain because of Him; and He did not speak of any other cross, but of the suffering which He should Himself undergo first, and His disciples afterwards. For this purpose did He give them this exhortation: “Fear not them which kill the body, but are not able to kill the soul; but rather fear Him who is able to send both soul and body into hell;” [thus exhorting them] to hold fast those professions of faith which they had made in reference to Him.Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg. 447

And for this reason, indeed, when at this present time the law is read to the Jews, it is like a fable; for they do not possess the explanation of all things pertaining to the advent of the Son of God, which took place in human nature; but when it is read by the Christians, it is a treasure, hid indeed in a field, but brought to light by the cross of Christ, and explained, both enriching the understanding of men, and showing forth the wisdom of God.Irenaeus (A.D. 180) Ante-Nicene Fathers vol.1 pg. 496

He knows accurately the declaration, “Unless you hate father and mother, and besides your own life, and unless you bear the sign [of the cross].” For he hates the inordinate affection: of the flesh, which possess the powerful spell of pleasure; and entertains a noble contempt for all that belongs to the creation and nutriment of the flesh. He also withstands the corporeal soul, putting a bridle-bit on the restive irrational spirit: “For the flesh lusts against the Spirit.” And “to bear the sign of [the cross]” is to bear about death, by taking farewell of all things while still alive; since there is not equal love in “having sown the flesh,” and in having formed the soul for knowledge. Clement of Alexandria (A.D. 195) Ante-Nicene Fathers vol.2 pg.546

In the same way the martyrs bear witness for a testimony to the unbelieving, and so do all the saints whose deeds shine before men. They spend their life rejoicing in the cross of Christ and bearing witness to the true light. Origen (248 A.D.) Ante-Nicene Fathers vol.9 pg. 343