Part 14 of Kingdom Life
Text: Matthew 5;33-37
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“Let what you way be simply ‘Yes’ or ‘No’; anything more than this comes from evil” (Matt. 5:37).
Sometimes when you tell someone you’ll do something, they ask, “Do you promise?” Why do people want us to say, “I promise”? Because they have doubts that we’ll really do what we say we’ll do. We live in a world of broken promises.
People of Integrity
Why is it important that we keep our promises? In a world of broken promises, followers of Jesus are to be different. We are to be people of integrity.
Being a person of integrity is an effective way to display the life-changing power of the gospel.
An Oath Is a Serious Thing
“You have heard that it was said of those of old, ‘You shall not swear falsely, but shall perform to the Lord what you have sworn’” (v. 33). Jesus is summarizing what the OT says about oaths. Oaths are “invocations of God or of some sacred object to undergird a statement or promise.”  “You shall not swear by my name falsely, and so profane the name of your God: I am the LORD” (Lev. 19:12). “If a man vows a vow to the LORD, or swears an oath to bind himself by a pledge, he shall not break his word. He shall do according to all that proceeds out of his mouth” (Num. 30:2).
The Abuse of Oaths in Jesus' Day
When you were a kid, did you think you didn’t have to keep a promise if your fingers were crossed?
In Jesus’ day, the Jews believed that some oaths were binding and some weren’t.  According to Jesus, there is no hierarchy of oaths. Every oath invokes God’s name in some way. If you swear by heaven, “[heaven] is the throne of God” (v. 34). If you swear by earth, “[the earth] is [God’s] footstool” (v. 35). If you swear by Jerusalem, “[Jerusalem] is the city of the great King” (v. 35). If you swear by your head, your head (i.e., your physical life) is under God’s control (“you cannot make one hair white or black,” v. 36).
Oaths Should Be Unnecessary
Jesus declares, “But I say to you, Do not take an oath at all” (v. 34). Jesus adds, “Let what you say be simply ‘Yes’ or ‘No’; anything more than this comes from evil” (v. 37; cf. James 5:12). Honest people don’t require oaths.
We are to be people of such integrity that we will be trusted without taking an oath.
Is it wrong for a Christian to take an oath (e.g., in a court of law)? Apparently not since Jesus himself testified under oath in his trial before the Sanhedrin (Matt. 26:63-64). 
Let Your "Yes" Be Yes and Your "No" Be No
In this passage, Jesus is mainly speaking against deliberate deception. If we profess to be Christians but lack integrity, we profane the name of Christ.
Sometimes we can break our promises for reasons other than deception. Sometimes we make a promise we shouldn’t because we want to please people. We sometimes say to someone, “I’ll remember you in my prayers,” but don’t ever pray for that person. Sometimes we neglect church commitments that are considered less important.
We must see ourselves as representing Christ in this world. We must strive to be people of integrity.
 R. T. France, The Gospel of Matthew, 213.
 Jesus also condemns this wrong belief about oaths in Matthew 23:16-22.
 God “guaranteed [his promise] with an oath” (Heb. 6:17). Paul writes, “Before God, I do not lie!” (Gal. 1:20).