Why was (and is) Christ "despised and rejected by men"?
First, because He required inward purity. Herein is the great difference between all human religions and the Divine religion. All human religions concern themselves with external performances—but the Christian religion is only concerned with the source of all conduct. "Man looks on the outward appearance—but the Lord looks on the heart" (1 Sam. 16:7). It was Christ's exposition and enforcement of this truth, which made Him so unpopular with the leaders. "Woe to you, teachers of the law and Pharisees, you hypocrites! You clean the outside of the cup and dish, but inside they are full of greed and self-indulgence. Blind Pharisee! First clean the inside of the cup and dish, and then the outside also will be clean. Woe to you, teachers of the law and Pharisees, you hypocrites! You are like whitewashed tombs, which look beautiful on the outside but on the inside are full of dead men's bones and everything unclean. In the same way, on the outside you appear to people as righteous but on the inside you are full of hypocrisy and wickedness!" (Matthew 23:25-28).
Why was Christ "despised and rejected by men"? Second, because He demanded repentance. "Repent—and believe the Gospel" (Mark 1:15) was His claimant call—that order is unchanging, for it is impossible to savingly believe the Gospel until the heart is contrite. Repentance is taking sides with God against ourselves—it is the unsparing judgment of ourselves because of our high-handed rebellion. It is a ceasing to love and tolerate sin, and excusing ourselves for the commission of it. It is a mourning before God because of our transgressions of His holy Law. And therefore did Christ teach, "Unless you repent—you shall all likewise perish!" (Luke 13:3), for He would not condone evil. He came to save His people from their sins—and not in them.
Why was Christ "despised and rejected by men"? Third, because He insisted on the denial of self, and this at two principal points, namely, the indulging and the exalting of self. All fleshly lusts are to be unsparingly mortified, and self-righteousness is allowed no place under the Gospel scheme. This was made unmistakably plain by our Lord's teaching, "If any man will come after Me—let him deny himself, and take up his cross, and follow Me" (Matt. 16:24). Yet nothing is more contrary to the desires of the natural man, and Christ's insistence upon these terms of discipleship causes Him to be "despised and rejected by men."
How is Christ "despised and rejected by men? In different ways and in varying degrees—professedly and practically, in words and in works. It is most important that this should be clearly recognized, for Satan deceives a great many souls at this point. He deludes them into supposing that because they are not guilty of what pertains to the avowed infidel and blatant atheist, therefore they are innocent of the fearful sin of slighting and defying the Lord Jesus. Ah, my reader, the solemn fact remains, that there are millions of people in Christendom who though not atheists and infidels—yet despise and reject the Christ of Scripture! "They profess to know God, but they deny Him by their works. They are detestable, disobedient, and disqualified for any good work!" (Titus 1:16). That verse clearly enunciates this principle.
Because of the limited space at our disposal, we are obliged to condense this last division so that the preacher will have to develop it for himself. Christ's authority is "despised" by those who disregard His precepts and commandments. Christ's yoke is "rejected" by those who are determined to be Lord over themselves. Christ's glory is "despised" by those who bear His name yet have no concern whether their walk honors Him or no. Christ's Gospelis "rejected" by those who on the one hand affirm that sinners may be saved without repenting of and turning away from their sins, and on the other hand by those who teach that Heaven may be won by our own good works.
There are some who intellectually reject Christ, by repudiating His claims, denying that He is God the Son, assumed a holy and impeccable humanity, and died a vicarious death to save His people from their sins. There are others who virtually and practically reject Christ. Just as there are those who profess to believe in the existence of God, own His power, and talk about His wondrous handiwork—yet who have not His fear upon them and are not in subjection to Him. So there are many who claim to trust in the finished work of Christ—yet their daily walk is no different from that of thousands of respectable worldlings. They profess to be Christian—yet are covetous, unscrupulous, untruthful, proud, self-willed, uncharitable; in a word, utterly unChristlike!