May I propose to you that these bumper stickers are simply intolerant? They are a reflection of the religious relativism ideology that says essentially that "all religions say the same thing", and that Jesus is no different from Muhammad, Buddha or "the rest of the boys." But is this bumper sticker really tolerant as some might try to promote?
It all depends on how one views tolerance and the whole toleration issue. What does the culture decry? The "new toleration" (which is really nothing new since the first lie in the Garden) is that you and I need to affirm and accept the differences between people, even the theological ones; and that we need to make it our primary goal not to offend anyone with our beliefs. In practical terms, this means that people who believe in absolute truth must keep quiet about their convictions, in order to avoid offending others.
In the light of this bumper sticker it means embracing and affirming all peoples' beliefs as no different from yours, a Muslim's, a Hindu's, a pagan's, and on and on and on. The problem with this whole issue is that the word and the message of the COEXIST bumper sticker is that one cannot embrace two or more beliefs which are antithetical to one another. Using the bumper stickers letters let me explain what I mean by this.
Let's look at it by way of each of the letters.
The "C" is the crescent moon and star of Islam. Despite the culture caving in to a Muslim worldview through laws and practices in pocket of this country, Islam is one of the most intolerant religions vying for world prominence. If you are not a Muslim then you are an infidel is essentially the attitude of this religion. Also if you look at the meaning of the word, "Islam" it does not mean peace. It means "submission." Submission to what you might ask? It means submission without mixture of anything else to the religion of Islam, the teachings of Muhammad, the Qur'an and the Hadiths. If you and I were not to submit, then it is the "or else". . . Does Islam sound like it wants to coexist with all the other religious and social ideologies? I think not.
The "O" is the peace sign refers to pacifism. . . militant pacifism. In fact if you are not a pacifist you are something else like a "warmonger," or someone filled with hate and vengeance. Look at the world around us though. We are in a world where, as it would appear to reflect a history of increasing violence. Politics and religious ideologies, even pacifism are not very tolerant if they think that everyone needs to be a pacifist. In fact, Jesus' statement in the second part of the Great Command, "love your neighbor as yourself" is in my mind the higher ethic and a fulfillment of what I call the horizontal commandments (man toward man) of the 10 Commandments.
The "E" on this bumper sticker as one of the symbols for "gay rights." If you don't know already, that those pushing for acceptance of the gay agenda, do not want to just get "married." They are pushing for full acceptance into mainstream society. While they may want to have the full benefit of "coexistence", there are those who embrace the moral law found within the monotheistic religions. Judaism, Christianity, and Islam all have laws with consequences speaking to what God calls homosexuality, "an abomination". Coexistence is impossible here on both sides of the issue would you and I agree?
The "X" is symbolic of the Star of David of Judaism. Have you ever wondered why there are there five different categories of Judaism?. Speaking of coexistence, why in the world do people hate the Jews? Why do militant Muslims want to push the nation of Israel out of existence. Sounds like if anyone should be desiring "coexistence" in our world it should be those who embrace and recognize as their own, the "star of David." This has been a problem for Israel and those of Jewish heritage ever since they left 430 years of captivity in Egypt in 1446 BC. Oi vey!
The "I" in this bumper sticker is symbolic of paganism. Paganism is about the worship of nature; and a rejection of worshiping the one true God and Creator "who is forever praised/blessed" (Romans 1:25). And the symbol is trying to say that those who embrace Christianity, Judaism and Islam need to "buck up" and affirm paganism as equal ideology. Can we coexist in a culture with those who profess to be pagan in their religion? Yes, so long as I don't have to affirm the pagan worldview equal with my embracing of historical Christianity. However that is not what the bumper sticker is promoting. What is this? Intolerant.
The "S" is Dao of Buddhism or better wise known as the "yin" and "yang". According to the Dao, everything, all of the self, all of nature, all of the genders are in balance. Good and evil are in balance (karma). All of nature is in balance and on and on and on. The problem with this is multifold which space and scope will not allow. Can we as Christians coexist together with those who embrace Buddhism or the Dao? Of course we can. Do I have affirm that my thoughts on the problem of sin and God's remedy as equal to Buddhism's fulfilling the 8 Fold Path and the Four Noble Truths as equal? Absolutely not! What is the bumper sticker telling us we should do? Do you see something intolerant in that "thayar" bumper sticker? I do.
The "T" is the cross of Christianity. But the question is whose interpretation of Christianity? Is it a liberal softened down, watered down version that says "God is love" and that we need to "love" everybody. Of is this the Christianity that say that the one who is love Incarnate has commanded us to "love the Lord our God with all our heart, and with all our soul and with all our mind. . .and to love our neighbor as ourself"?
What I do find interesting about the bumper sticker is that it is decrying the desire for everyone to get along and live in harmony. That is a good thing. The problem is that every one who embraces the ideologies symbolized on the sticker, embraces those ideologies or religions with the thinking that they are believing in the only right religion or view. The bumper sticker is not only expressing an intolerance, but also a hypocrisy that is quite characteristic of cultural relativism and religious relativism.
A final thing I find interesting from all these "intolerant" symbols in the COEXIST sticker is that all these ideologies represented in their contexts are ultimately reactions against the cross of Christ, except possibly the cross for Christianity. That depends on the individual's understanding of the sticker's symbol. Nevertheless, it was at the cross where Jesus Christ was sacrificed, as a demonstration of real love, as an act of forgiveness for a sinner's salvation and justification before a holy, loving and righteously just God. But Jesus' crucifixion was carried out by those who could not "coexist" with love incarnate; who could not coexist with one who said truthfully that He was the only "way and the truth and the life."; and that "no one comes to the Father but through Me (Jesus)." (John 14:6)
What is more tolerant? That depend on what you and I mean by tolerant. If you would like to read what this buzzword is all about please see my posting on Responding to Cultural Buzzwords. This will help you see more what the problems are with the misunderstanding of tolerance, relativism, and multiculturalism. They are all a ruse that won't work since they are all contradictions in terms and violating cardinal laws of critical thinking. This is something our culture has definitely lost.
Instead we post stickers on the back of our vehicles, thinking that we are tolerant, but we are most intolerant if you violate my thinking with a view that I have to engage. In the words of Professor Kirke, in C. S. Lewis', "The Lion Witch and the Wardrobe",
"Odd things they say, even their looks will let the secret out. Keep your eyes open. Bless me what do they teach them at these schools?"
 As Christians, there is a certain degree of tolerance we must have, but we must remember that it is not the primary quality we're to build in our lives. We are to be committed to a number of things, including the truth which is the Word of God, and the things which are taught by that truth, such as justice, because we worship a God who is just and righteous. But there are times we ought to be tolerant in order to pursue justice and times when we should not. Turning the other cheek is a good example.
 There are other looks to the bumper sticker that are incorporating strictly religious ideologies. The one for this posting seems to be the most popular of the ones that I have seen. It is more toward an ideological bent than a strictly spiritual one.
 Matthew 22:39
 That is the last 6 of the 10 Commandments and the giving of those laws by God to Moses found in the Pentatuch.
 By monotheistic religions, I am referring to the belief in one God who is "personal", transcendent, absolute in power, knowledge and presence and holiness. The three that profess the belief in a God like this are Judaism, Christianity and Islam (though Islam unlike the other two would say that God has not and does not intervene).
 Orthodox (these are the true "by the Book" conservatives), Conservative (are not so conservative), Reform (are reforming Judaism to a more tolerant liberal understanding of the Torah and the Mitzvot), Liberal and "Jew-boos" (those who embrace and mix Judaism with Buddhism).
 By "love" I am talking here about a love that is devoid of holiness, justice, forgiveness, and those things that truly reflect the nature of the God of the Bible.
 Please see the context of Matthew 22:34-40.