Mark 8:38

"Whoever" means unbelievers or believers (cf. Mark 8:34). For unbelievers living when the Son of Man returns to set up His kingdom, Jesus being ashamed before the Father will result in their loss of salvation. For believers living then, it will mean their loss of reward. This is the first explicit reference in Mark to Jesus’ return in glory. Being ashamed of Jesus, rejecting His claims, has serious consequences.

". . . this conflict between Jesus and the disciples on the way to Jerusalem exemplifies the clash between the values of the disciples and those of Jesus." [Note: Rhoads and Michie, p. 91.]