As we often do not see ourselves deceiving and insulting others, we are capable of all that. If we are capable, then we are guilty as charged by the scripture. When Jesus was here on earth, He was the only one human being who never lied, deceived, nor slandered. "He committed no sin, neither was deceit found in his mouth." (1 Peter 2:22) Glory goes to Him as the Lamb of God without blemish who took our place!