People often reject the gospel due to a natural rebellion against God's truth.
The rejection of the gospel message stems from humanity's inherent sinful nature, which opposes the truth of God's Word. In Acts 18, we see that while Paul preached the gospel, many both accepted and rejected his message. Those who opposed Paul's preaching reacted because they preferred their self-righteousness and traditions over the simplicity of grace through faith in Christ. As Scripture informs us, it is God who opens hearts to accept the truth (Acts 18:10-11), demonstrating that ultimately, the differentiation between believers and non-believers is due to God's sovereign mercy towards His chosen ones, as stated in Romans 9:15-16.
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