No matter how many people you talk to about your Christian faith you will never find more than three categories for why people reject the offer of the gospel. Those three reasons are Intellectual, Emotional and Volitional.

Intellectual: Some people you talk to about Christ will not accept what you are saying on account of the fact that they don’t find Christianity intellectually viable. Their understanding of science or philosophy or history does not accord with Christianity or their perception of Christianity. Perhaps they believe the existence of evil/suffering makes the Christian idea of God impossible or their commitment to science and the belief in philosophical naturalism makes them reject the possibility of Jesus’ resurrection. Their worldview is fundamentally incompatible with Christianity and therefore they reject it. This is true not just of Atheism but of any worldview which collides with the Christian worldview including other religions like Islam or Hinduism, etc.

Emotional: Some people will reject Christianity for irrational reasons and their objection is purely emotional. That is to say they don’t have an intellectual issue such as thinking there is insufficient evidence to believe God exists or that Jesus rose from the dead, but perhaps they have been hurt by someone who was a Christian and this has poisoned the well. They were cheated by a business man who claimed to be a Christian, abused by a caregiver who claimed to be a Christian, or they grew up in church and saw a lot of hypocrisy. None of this is evaluative of the intellectual validity of Christianity, but they don’t want anything to do with it because they’ve been emotionally jaded to it.

Volitional: Some people will not accept Christianity simply because they don’t want to. It’s not that they don’t think Christianity is intellectually viable, and it’s not that they’ve had a particularly bad experience that has turned them off to Christianity, rather, they know that Christianity would require more from them than they want to give. Becoming a Christian requires devotion to God and actively attending a church and they’d rather sleep in on Sundays and spend their time otherwise engaged with things that interest them more. Christianity may be true, but becoming a Christian would mean having to stop sleeping with their girlfriend outside of marriage, or even to give money to the church or poor people. In many cases this group has religion on the backburner; they’ll get to it, just maybe later when it’s more convenient.

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Above all, each category of person needs prayer. The overarching reason people reject the Christian message is because of their own depravity. They are dead in their trespasses and sin (Ephesians 2:1-10) and they do not seek for God (Romans 3:10-12) and the have exchanged the truth about God for a lie (Romans 1:18-32) and Satan has blinded their minds (2 Corinthian 4:4). God commands out apologetics effort (1 Peter 3:15) and he uses that as he draws people to himself. But ultimately people’s condition, no matter how it gets expressed, Intellectual, emotional or volitional, is a bi-product of their depravity. So pray for them, always start and end with the gospel, and try to address them where they are at.