“will confess.” The verb is in the future tense and the context is people who testify of Jesus will be dragged before the authorities and interrogated and beaten (cp. Matt 10:16-20). Those will be difficult times. People who continue to confess Christ as Lord will be tortured, imprisoned, and even killed. There will be great temptation to simply deny the Lord to be set free, but Jesus warns us to continue to confess him in those difficult times, and if we do, he will confess us before the Father.