And I tell you, everyone who acknowledges me before men, the Son of Man also will acknowledge before the angels of God, but the one who denies me before men will be denied before the angels of God.
The context of this statement from Jesus is the warning of increased persecution that would come from Israel's religious leaders againt the disciples of Jesus (Luke 12:1-12). He has warned his disciples to steer clear of the hypocritical religion of the Pharisees. God makes all secrets known in His refining justice, so hypocrisy will always eventually be revealed by Him.
The fear of a disciple of Jesus is not for what man can do to any person. Instead, we respect God's justice, Who alone can determine eternal destiny. Human powers might give a death sentence, but God can judge sin and souls in hell. God knows us and cares for His own. But we must fear Him and not human powers.
True disciples of Jesus then will not be coerced by human torture or punishment into denying their Lord. They will resolutely acknowledge the Son of Man before the men who bring persecution. They will hold fast to Him because their souls are safe in Christ. No human misery outweighs the splendor of eternity loved by God in Christ.