How do we know that God demands perfection?

In Romans 2, it is clear that God’s judgment is based on truth and holiness. Paul emphasizes that 'the judgment of God is according to truth' and makes it clear that individuals cannot escape judgment without perfection. While many modern teachings may suggest that God only requires a good effort, the reality is that absolute perfection is what God demands, as reflected in His divine law. This understanding serves to illustrate the impossibility of achieving salvation through human effort, pointing instead to our absolute need for grace through Christ.