Some preachers say the Sermon on the Mount is the Constitution for Christian Living, or call it a Manifesto for the Life of a Follower of Christ.
Don’t you believe it. Such teaching is nothing more than legalism dressed up in fancy phrasing.
Take a look at the language Jesus used in the first part of the sermon, immediately following telling his listeners they need to be more righteous than the Pharisees. He covers some of the biggest moral issues imaginable, both in his day and ours – murder, adultery, divorce, promises, vengeance, and love – and tells them about each: “You have heard that it was said … but I tell you … .” (Matthew 5:21-22, 27-28, 31-32, 33-34, 38-39, 43-44.) Six times Jesus points out that their understanding of a righteous life under the laws of Moses was insufficient.
He closes the sermon by speaking in various ways on the single point of doing God’s will, including the sobering comment: “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father who is in heaven.” (Matthew 7:21.)
Jesus couldn’t be clearer: you can’t enter God’s kingdom unless you do the will of God the Father. Many have taken that phrase and jumped to the conclusion that in order to be a Christian they have to do everything – everything! – Jesus described in the sermon he just preached: they can’t hate another person because that’s the same as murder (Matthew 5:22), they can’t look at someone with lust because that’s the same as adultery (Matthew 5:28), etc.
If that’s what Jesus meant, then no one enters the kingdom of God because no one is good except God. Jesus was clear on that too.
A certain ruler asked him, “Good teacher, what must I do to inherit eternal life?”
“Why do you call me good?” Jesus answered. “No one is good—except God alone. You know the commandments: ‘You shall not commit adultery, you shall not murder, you shall not steal, you shall not give false testimony, honor your father and mother.’” (Luke 18:18-20.)
When it comes to doing God’s will, though, Jesus told his friends it’s not about following a set of commandments on murder and adultery, stealing and lying.
Jesus said it’s about Jesus.
Then they asked him, “What must we do to do the works God requires?”
Jesus answered, “The work of God is this: to believe in the one he has sent.” (John 6:28-29.)
That’s all it takes. Believe in Jesus.
Believing That Jesus Is All You Need
How can mere belief be a work of God? Because it means you acknowledge Jesus the same way your Father in Heaven does: that Jesus is God himself.
No one who denies the Son has the Father; whoever acknowledges the Son has the Father also. (1 John 2:23.)
And this is his command: to believe in the name of his Son, Jesus Christ, and to love one another as he commanded us. (1 John 3:23.)
… but every spirit that does not acknowledge Jesus is not from God. (1 John 4:3.)
Yet what is it about Jesus that means believing in him is all it takes to do God’s will? Jesus is the one who has perfectly lived out the Father’s will, and now we benefit from that and are counted as righteous along with Jesus, that’s what it means.
But now apart from the law the righteousness of God has been made known, to which the Law and the Prophets testify. This righteousness is given through faith in Jesus Christ to all who believe. (Romans 3:21-22.)
Christ is the culmination of the law so that there may be righteousness for everyone who believes. (Romans 10:4.)
It is because of him that you are in Christ Jesus, who has become for us wisdom from God – that is, our righteousness, holiness and redemption.(1 Corinthians 1:30.)
Some will insist that even though Jesus made us righteous, all that means is that you are now able to live righteously, now able to follow all those laws, and that the Sermon on the Mount is your guidebook for how to do that. Those people are wrong. Our lives are not about righteous living but about living a life of faith through God’s grace.
I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing! (Galatians 2:21.)
[I do not have] a righteousness of my own that comes from the law, but that which is through faith in Christ – the righteousness that comes from God on the basis of faith. (Philippians 3:9.)
You might think, though, that this righteous life of faith through grace has eluded you for one simple reason: you keep on sinning.
Join the club, my friend.
Paul said, “I do not understand what I do. For what I want to do I do not do, but what I hate I do.” (Romans 7:15.) He was talking about the sin that remained in his life even after he had become a believer, been sent out as a missionary, and established churches throughout the eastern portion of the Roman Empire. He still sinned. Sound familiar?
John (one of Jesus’ closest friends) had an assurance for people like Paul – people like you and me:
My dear children, I write this to you so that you will not sin. But if anybody does sin, we have an advocate with the Father – Jesus Christ, the Righteous One. He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world. (1 John 2:1-2.)
How do you know that Jesus’s righteousness is fulfilled in you, though? You know because Jesus is “the author and perfecter of faith“, the one who originated (authored) your faith and perfected (completed) it for you. (Hebrews 12:2.)
This is what Jesus does.
Righteousness is found in him because he is the source of righteousness, and it is found in you because you belong to him and he has placed the Holy Spirit in you.
And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession – to the praise of his glory. (Ephesians 1:13-14.)
Look at the words in that passage: Christ, salvation, believed, Holy Spirit, guarantee, inheritance, God’s possession. You are God the Father’s possession, and God the Holy Spirit guarantees your inheritance with Jesus, who is God the Son.
Do you see? This is not about you and your [in]ability to follow rules Jesus preached in the Sermon on the Mount to those under the law of Moses. This is about God who has shown his grace in giving you the righteousness that Jesus himself achieved.
As the Bible says, this is for “the praise of his glory.”
Believe in Jesus, then. That is the work of God in your life. And in your belief, God gets the glory and praise.