Since God is “a God of truth” (Deuteronomy 32:4), it makes sense that the words proceeding forth from His mouth would reflect and demonstrate the same nature as their author. According to the scriptures, this is exactly what has happened. The psalmist said, “thy law is the truth” (Psalm 119:142) “and all thy commandments are truth” (Psalm 119:151). The Lord Jesus confirmed this when He said, “Sanctify them through thy truth: thy word is truth” (John 17:17). If God is worthy of praise for being a God of truth, it only makes sense that His truth would also be worthy of man’s praise (Psalm 71:22). God, knowing this truth, magnified His word above all His name (Psalm 138:2).
A basic definition of communication involves making things common. When we speak to others, we express what is in our minds and hearts making those thoughts common with others. The Bible warns the believer in Ephesians 4:29 to “Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.” The words that come out of our mouths should edify or build up others, not demean and degrade them. They should be strengthened by what we say. Keep in mind that corrupt communications weaken the believer (1 Corinthians 15:33). This is why Christians are instructed to put off all “filthy communication” (Colossians 3:8).
Our verbal communications involve the words that spring forth from our mouths. No doubt, the Lord considers these communications important and we should too. In today’s passage, the Lord gave some specific insights concerning His expectations of our communication. First, He wants our communication to be short and to the point – “let your communication be, Yea, yea; Nay, nay” (Matthew 5:37; see also Proverbs 10:19; Ecclesiastes 5:3, 7). Second, our word should be validated without the necessity of certifying it with vows, oaths, and swearing. In the context of the passage, the Lord Jesus forbade swearing “by heaven” (Matthew 5:34), “by the earth” (Matthew 5:35), or “by thy head” (Matthew 5:36). When we swear by these things, we put ourselves in danger of condemnation (James 5:12). Let your nay be nay and your yea be yea!
