Brothers, do not choose to have the minds of children. Instead, be free of malice like infants, but be mature in your minds
Other versions
King James Version
Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be men. English Standard Version
Brothers, do not be children in your thinking. Be infants in evil, but in your thinking be mature.New International Version
Brothers, stop thinking like children. In regard to evil be infants, but in your thinking be adults.