Words are like faith vehicles; they transmit faith or unbelief. But I don’t like that; you don’t make the rules. It’s alright to joke around, but be careful how you do it. Retrain your heart but renewing your mind according to the Word of God. I can think of a couple of personal examples where I joked and was very sarcastic about “well this will probably happen to me now” It is too personal to share, but all I can say is that it really shouldn’t have happened, but it did. I believe my unbelieving words caused it to happen. Remember the little children’s chorus “be careful little lips what you say.” Romans 10:9, 10*** and many other scriptures tell us about this heart (faith) and words (mouth) connection. Our words do matter? We just don’t think they do. If we don't take our words seriously then it confuses our heart and when we need to believe for something; our words don't work because our heart thinks we are joking. I challenge you to reconsider your position on this. I know I did and it changed my life for the better!!!
***Scripture reference- “that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved.”
“For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation.” (Romans 10:9.10) (NKJV)