'Generation' in the Bible

and having sighed deeply in his spirit, he saith, 'Why doth this generation seek after a sign? Verily I say to you, no sign shall be given to this generation.'

for whoever may be ashamed of me, and of my words, in this adulterous and sinful generation, the Son of Man also shall be ashamed of him, when he may come in the glory of his Father, with the holy messengers.'

And he answering him, said, 'O generation unbelieving, till when shall I be with you? till when shall I suffer you? bring him unto me;'

Verily I say to you, that this generation may not pass away till all these things may come to pass;