How do I know if something is a sin?

This is one of the most practically important questions in the Christian life, and the answer requires more than a simple list — because the Bible gives us both specific commands and principles that help us navigate the vast territory of decisions Scripture does not address directly.

Start with what the Bible clearly says. Some things are plainly identified as sin throughout Scripture — sexual immorality, theft, murder, lying, idolatry, drunkenness, greed, slander (see Galatians 5:19-21, 1 Corinthians 6:9-10). These are not grey areas. If Scripture calls something sin, it is sin, regardless of how accepted it is in wider culture or how much pressure you feel to accommodate it.

Then there are matters the Bible does not directly address — the countless decisions of modern life that were not in view when Scripture was written. Here, several principles from Paul's letters help:

The glorification test. 1 Corinthians 10:31: "Whether you eat or drink, or whatever you do, do all to the glory of God." Ask honestly: can I do this in a way that glorifies God, or does it inevitably pull me away from Him?

The lordship test. 1 Corinthians 6:12: "All things are lawful for me, but I will not be enslaved by anything." Is this thing controlling me in a way that belongs to God alone? Anything that becomes a functional lord in your life has become an idol.

The body test. 1 Corinthians 6:19-20: Your body is a temple of the Holy Spirit. Does this damage or degrade the body God has given you?

**The conscience test.*

• Romans 14:23: "Whatever does not proceed from faith is sin." If you genuinely cannot do something with a clear conscience before God, that is a signal — even if others would not share your conviction.

**The stumbling block test.*

• Romans 14:21: Would doing this cause a weaker believer to do something against their own conscience? Love sometimes calls for restraint of what is lawful.

If something passes all these tests — if you can do it thankfully, to God's glory, with a clear conscience, without harming yourself or causing others to stumble — you are likely in the territory of Christian freedom. Use it well.