
I fear that many Christians make Christianity far more complicated than they need to make it. Christianity is about Jesus of Nazareth, period. Christianity is about who Jesus is, what he claimed, and ultimately, it is about whether or not he rose from the dead.
Let's take the last one first. Did Jesus rise from the dead after having been crucified? If the answer is no, then Christianity is a total waste of time. This is not simply conjecture, it is what the apostle Paul taught. He wrote, "If Christ has not been raised, then our preaching is in vain and your faith is in vain. We are even found to be misrepresenting God that he raised Christ, whom he did not raise if it is true that the dead are not raised...if Christ has not been raised, your faith is futile and you are still in your sins...if in this life only we have hoped in (the resurrection of) Christ, we are of all people most to be pitied" (1 Corinthians 15:14-19).
It breaks down like this:
1. If Jesus did not rise from the dead, preaching Jesus is worthless.
2. If Jesus did not rise from the dead, your belief in Jesus is worthless.
3. If Jesus did not rise from the dead, you lie about God when you tell people he did.
4. If Jesus did not rise from the dead, Paul is self-admitted liar.
5. If Jesus did not rise from the dead, Christians are pitiful.
It really is that simple. Christian, if Jesus did not rise from the dead, do something else.
However, if Jesus did rise from the dead, then that is spectacular. People don't just get up from the grave after being dead for three days. And, as Paul goes on to write, "In fact, Christ has been raised from the dead" (1 Cor. 15:20). It is in this resurrection from the dead that Jesus' teachings and and "Christ" title are validated. Again, Paul writes that Jesus was "declared to be the Son of God in power according to the Spirit of holiness by his resurrection from the dead" (Romans 1:4).
Technically speaking, crucifixion is not that awesome. Lots and lots of people were crucified in the first century. However, rising from the dead is a marvelous feat to say the least. Since Jesus rose from the dead, it means that he merits an audience. We ought to listen to this man and what he taught because he alone has the answer to death. He is only one to defeat it.
So ask yourself, if you are a Christian. Is this what defines you? Is this what your co-worker would say defines you? Do they know that you do what you do because Jesus conquered death? Do they know that you obey Jesus because you believe him to be both Lord of all Creation, Conqueror of Death, and Savior of Mankind, and that you believe this because he rose from the dead?
Or do they think that you are simply a moralist? They probably know about your "do and don't do" list, but do they have any idea how you got that list? Do you implicitly or explicitly impose that list onto others without speaking of the resurrection of the dead?
What I mean by that is this: When someone advocates a cause or behavior that you know is not pleasing to the Lord, is your first impulse to declare yourself against it, or is your first impulse that you need to speak about Christ's resurrection? Because if you say what you are against wihtout giving the foundation for why you are against it, you are going to hang yourself out to dry at best, and at worst you will become a moralist.
So talk more about the resurrection of Jesus and the fact that he has the power to grant eternal life. Then, having talked about that until you are certain that everyone knows you are obsessed with it, you may then proceed to unpack why you are for or against certain behaviors.