Why is it important that God looks at the heart and not outward appearances?

God's perspective is fundamentally different from ours; while we often judge based on outward appearance, as noted in 1 Samuel 16:7, God looks upon the heart. This principle is vital for Christians, as it underscores that our standing before God is based on inner faith and sincerity rather than external acts. In the case of Joshua in Zechariah 3, his filthy garments represent the heart's corruption, yet through grace, God sees beyond this to the righteousness He provides. This illustrates that our worth is derived from our relationship with Christ, who cleanses and transforms us from the inside out.