What are five things that both atheists and Christians have in common? What are things that they both believe in? What can Christians and atheists both agree on?
A Definition of Atheists
The word atheist is attaching an “a” to the word theist. A theist is a person that believes in God so an atheist is one who doesn’t believe in God. By attaching an “a” prefix to a word, the opposite of that word becomes true. For example if someone is an atypical person, they are not a typical person. If a person is said to be amoral, then they have no morals or not normal morals. The atheist either denies or disbelieves that there is God or any supreme being for that matter. God does not exist in their thinking even though it is impossible for them to prove it conclusively. They often provide arguments from reasons of silence. One atheist told me that if there is a God then why is there evil . I said since you are convinced that there is no God, guess what…there is still evil in your non-God world. I told him that since he was convinced that there is no God and there is still evil in the world evil still exists. You believe that there is no God but having no God has not eliminated evil in the world so evil must exist even if there is no God. By the way, God did not create evil, He created beings with free will with the capacity to do both good and evil. If they deny evil then do they also deny good? Is murder not evil? Is robbing a poor person not evil? If good exists then so must evil. Atheism is like Christianity in the sense that they are both faith-based beliefs. The only difference is that Christians have historical and archeological evidence among other things.
A Definition of Christians
The word “Christian” is literally a little Christ or Christ-like. A Christian by definition believes in Jesus Christ and they believe in His deity. That is, they believe that Jesus is God  and has always existed. If a person does not believe that Jesus is divine and fully God and has existed for all eternity, then they cannot by definition call themselves a Christian. They can call themselves “religious” or as belonging to a “religion” but not actually a Christian. A Christian believes that Jesus is God as opposed to the Mormons. Mormons for example believe that man can become God while Christians believe that God became Man…in the form of Jesus Christ. Christians believe that God is eternal and that Jesus came and lived a sinless life, died for the redemption of those who would trust in Him, that they can be saved by faith alone in Christ alone and that their works are never meritorious enough to save them. They also believe that Christ was resurrected from the dead, ascended into heaven, now sits at the right hand of the Father and is coming again to judge those who have rejected Him as Lord and Savior but He has already judged those who believe in Him as innocent by their faith in Him (2 Cor 5:21). They will be with Him in the Kingdom of Heaven for all eternity while those who refuse to trust in Christ will be eternally separated from God for ages without end (Rev 20:11-15).
Five Things Atheists and Christians Agree On
Natural Selection is one of those things that both Christians and atheists agree on. There is sufficient evidence in nature that living organism can adapt and change within their species according to their environmental demands. That is some birds may develop a longer beak to be able to feed on certain flowers or sources of insects. They may grow longer beaks but they are still birds and have not changed into a new life form. That is called microevolution but is better defined as natural selection. Macroevolution is where one life form changes into a new, different one. That is where the atheist and Christian part ways. Macroevolution occurs above the species level and creates not only new designs within the organism but new life forms. Christians do not believe in this because they believe in the Creator. There is also the roaring silence from the lack of evidence of transitory life forms which are not found anywhere in the fossil records. The Cambrian explosion is the best example of this.
For more on the Cambrian Explosion read: Why Christians need to know about the Cambrian Explosion 
The Beginning Point of the Universe
Another point where atheists and Christians can agree upon is that the universe had a finite, singular, beginning point. Some call it the Big Bang. If you wound back and reversed the now expanding universe, everything would return to a single point in time and space. Scientists believe that originally all the matter in the universe consisted of an extremely hot and dense singular point of matter. This theory is the one that most consistently explains the observations of the past and present states of the universe and is the most widely accepted theory within the scientific community.
There are Objective Morals
Most atheists and Christians agree that murdering someone innocent is wrong. There is a difference between murdering someone and killing someone. A police officer is not murdering someone who is trying to kill innocent people. He is trying to save the lives of bystanders and so he is killing a person who is trying to or has already murdered others who do not deserve to be killed. Both sides also agree that certain objective moral behaviors are wrong like abusing, sexually molesting or rapping children. It is also wrong to rob or torture people and to destroy private property. These are what are called universal, objective morals and even though there are a small minority of isolated societies that do some of these things, the vast majority of humanity, both atheist and Christian, realize that these are wrong. They are objectively wrong.
There is Objective Truth
Both atheists and Christians agree that postmodernism is wrong in the sense that some things are true regardless of beliefs or opinions. For example, 2 + 2 will always equal 4. That is a mathematical truth that is absolutely true and can never be considered as relatively true. It is either true or false. It cannot be both. No one can rationalize objective truth away. Imagine a 2nd grade teacher putting this problem up on the board and a student writing it down as 2 + 2 = 5. The teacher tells the student, “Robert that is wrong. 2 + 2 is 4.” The young student says, “Well that’s your opinion, to you it might be 4 but to me it’s 5 because that’s what I believe, therefore to me it’s 5 or any number I want.” There are some in the world that actually believe that there are no absolutes. One person actually told me once that “There are no absolutes!” My response was, “Didn’t you just refute this by telling me that there are no absolutes and being absolute about it? Are you absolutely sure of this? If so, then you just validated that there are absolutes!” Generally speaking both atheists and Christians believe in absolute truths.
There are Good People on Both Sides
Both atheists and Christians can agree that there are good people on both sides. Many Christians and many atheists have done much good in the world. Conversely, both sides have done bad things and so there are bad on both sides too. A person being good doesn’t qualify them for heaven or doing something bad doesn’t necessarily send them to hell. People can do all the good in the world and still not be good enough to go to heaven because they have to be perfect. This is humanly impossible even though there is a way or actually The Way to become perfect through a Person (2 Cor 5:21; John 14:6). A Christian can still sin but still make it into heaven if they confess their sins (1 John 1:9). They understand that they are not sinless (Rom 7)…even though they do sin less!
One thing that Christians agree on about their atheist friends, family, co-workers or even strangers is that God doesn’t want them to perish. He desires that all would be saved (2 Pet 3:9) and so do the great majority of Christians (Jude 1:22-23). We know that God doesn’t take pleasure in the destruction of men or women who refuse to believe in Christ (Ezk 18:23). My prayer is that we would love those who yet do not believe because it is God alone Who can open the hearts (Acts 16:14) but He does want us to participate in the proclamation of the gospel of Jesus Christ because how will they know and be saved if they do not hear (Rom 10:14). Can we agree on that?
Another article you might be interested in: Do Atheists Really Believe There is No God?