We are never to be ashamed of Jesus (Mk 8:38), His words, or the gospel (Rm 1:16). We should never be ashamed "of the law of the Most High and His precepts, or of the sentence to be passed upon the sinful" (Sir 42:2). We should never be ashamed of taking measures to be just, cautious, and discreet (Sir 42:3-8).
We should always be ashamed of immorality, falsehood, flattery, crime, disloyalty, lying, stealing, overeating, stinginess, aloofness, impure glances, thoughts and actions, harsh words, insults, and betraying secrets (Sir 41:15-24).
By believing in Jesus, loving Him, and not being ashamed of Him, we receive the grace to resist temptations and not fall into the shameful consequences of sin. "There is no condemnation now for those who are in Christ Jesus" (Rm 8:1). Without a total commitment to Jesus, shame or a dead conscience is inevitable. Only in Christ are we truly shameless (see Ps 34:6) and living in the full dignity of a child of God. In Christ, live shamelessly.