Acts 1:10 While they were looking steadfastly into the sky as he went, behold, two "men" stood by them in white clothing, Acts 1:11 who also said, "You men of Galilee, why do you stand looking into the sky? This Jesus, who was received up from you into the sky will come back in the same manner as you saw him going away into the sky." -- RLIV.
Many cite Acts 1:11 and claim that the angels said Jesus would return in the flesh. Actually, the angels never said that Jesus was to return in flesh; this has to be assumed. Rather, the angels spoke of the "manner" in which Jesus was return, quite, without observation of the world, and known only to a few of his disciples. -- Matthew 24:37-39; Luke 17:10,26.
Indeed, Peter tells that Jesus died "in the flesh" for our sins. (1 Peter 3:18) And, in Hebrews 5:7, we read of the "days of his flesh" as being past. After his ascension, Jesus formally presented his body of flesh to his God as the offering for sin. -- Hebrews 9:11,12,24; 10:10.
Thus, for him to return in his former body of flesh would mean that he took back the offering for our sins.