Why does obedience to God matter?

from the old testament

• Adam and Eve failed to obey God’s command and thus brought the reality of death to humanity (Genesis 3; Romans 5:12).
• The Mosaic covenant (Exodus 19—24) had many commands the Israelites were to obey. When they collectively obeyed, God would bring national blessing; collective disobedience would lead to negative consequences (Deuteronomy 28).
• The obedience of Shadrach, Meshach, and Abednego to God’s commands led to the king of Babylon honoring the Lord (Daniel 3:28).
• King David realized the importance of keeping God’s Law. "Blessed are those whose way is blameless, who walk in the law of the LORD! Blessed are those who keep his testimonies, who seek him with their whole heart" (Psalm 119:1–2).
• Proverbs 1:8 says, “The fear of the LORD is the beginning of knowledge; fools despise wisdom and instruction.” Part of fearing the Lord is following His commands and living according to His ways. His ways are wise and life-giving.

from the new testament

• The fifth of the Ten Commandments taught Israel to honor their earthly fathers and mothers (Exodus 20:12). This is not just part of the Mosaic covenant fulfilled in Christ (Matthew 5:17); it is a command repeated for believers of Jesus as part of the new covenant (Ephesians 6:1–4). Children are to “obey [their] parents in the Lord.” Similarly, we are called to honor earthly authorities (Romans 13:1–7). Submission to those in authority over us is part of our expression of obedience to God.
• God is our heavenly Father, and we should honor and obey Him, as we should our earthly father. Obedience to God proves our relationship with Him (1 John 5:2–3), and we demonstrate our love and faithfulness through obedience, too (1 John 2:3–6).
• Jesus said, "If you keep my commandments, you will abide in my love, just as I have kept my Father's commandments and abide in his love. These things I have spoken to you, that my joy may be in you, and that your joy may be full" (John 15:10–11).
• In Matthew 22:36–40 Jesus tells us the heart attitude of obedience. A religious leader asked, “’Teacher, which is the great commandment in the Law?’ And [Jesus] said to him, ‘You shall love the Lord your God with all your heart and with all your soul and with all your mind. This is the great and first commandment. And a second is like it: You shall love your neighbor as yourself. On these two commandments depend all the Law and the Prophets.’”
• If we love God and our neighbor, we will act upon our love with works. James 1:22–25 says, "But be doers of the word, and not hearers only, deceiving yourselves. For if anyone is a hearer of the word and not a doer, he is like a man who looks intently at his natural face in a mirror. For he looks at himself and goes away and at once forgets what he was like. But the one who looks into the perfect law, the law of liberty, and perseveres, being no hearer who forgets but a doer who acts, he will be blessed in his doing."
• Paul and Silas's obedience to God led to the salvation of the jailer in Philippi (Acts 16:29–30).

implications for today

Paul wrote in 2 Corinthians 5:17, "Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come." Over and over, the Bible tells us that God blesses and rewards obedience (James 1:12–18). Obedience is also important because others are watching how we live, and our testimony should glorify God (Matthew 5:16). Obedience enables us to live a life of joy, without shame, rooted deeply in the Lord and confident in our eternal hope (Psalm 1:1–4; Jeremiah 17:7–8; 1 Peter 1). It is important to remember that while obedience to God is always the wisest and best option, it does not guarantee temporal comfort. In fact, “all who desire to live a godly life in Christ Jesus will be persecuted” (2 Timothy 3:12). Even so, we can fully trust that God is with us, and we can experience contentment and peace in Him now as well as confident hope for the future (Romans 8:28–30; Philippians 4:8–13; Hebrews 11).

The great news is that God is gracious. If we haven't been living for Him, if we haven't been following His commandments, if we've been living in and for the world, we can be transformed by the blood of Jesus Christ. We can ask God for forgiveness, and He will give it (Ephesians 2:1–10; 1 John 1:8—2:6). And He will choose to forget our sin, just as if we had never committed the sin in the first place (Psalm 103:12). It glorifies Him to do that because it is written, "'This is the covenant that I will make with them after those days, declares the Lord: I will put my laws on their hearts, and write them on their minds,' then he adds, 'I will remember their sins and their lawless deeds no more'" (Hebrews 10:16–17).