Contradiction with Acts 1:11
States Jesus will return in the same manner as he ascended, which does not explicitly mention coming in clouds as in Mark 13:26.
Acts 1:11: Which also said, Ye men of Galilee, why stand ye gazing up into heaven? this same Jesus, which is taken up from you into heaven, shall so come in like manner as ye have seen him go into heaven.
Contradiction with Luke 17:21
Suggests the kingdom of God is within you, implying a non-physical return, in contrast to the physical appearance in Mark 13:26.
Luke 17:21: Neither shall they say, Lo here! or, lo there! for, behold, the kingdom of God is within you. [within you: or, among you]
Contradiction with 2 Thessalonians 2:2
Warns against the idea that the day of Christ is at hand, suggesting a non-imminent return unlike the immediate expectations implied in Mark 13:26.
2 Thessalonians 2:2: That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
Contradiction with Matthew 24:24
Indicates false Christs and prophets will show great signs and wonders, which could contradict the clarity of seeing the Son of Man as described in Mark 13:26.
Matthew 24:24: For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if [it were] possible, they shall deceive the very elect.