Most of these scriptures do not refer to perfect people or perfect behavour, but coming in to a more complete understanding of what Christ has done for us.
I think this applies to most pauline (or sub-pauline) texts, but hardly to Matthew or James, who call for a radical, absolute, supramoral stance or attitude in life, without any reference to "what Christ has done for us".
By the way, in Matthew 19 I rather feel irony in the first part of the dialogue (v. 16ff), which sums up the "common morality" of the Decalogue (plus the Levitical "love your neighbour as yourself") and leads to the young man's admitting he is not satisfied with that (v. 20). The second proposition (v. 21), unacceptable as it was to the young man, was quite serious to Matthew, since the "perfection" it required is equated to "entering the Kingdom of heaven/God" in v. 23f.
I believe there is a definite strand of "perfection" teaching, both in Matthew and James, which is very different from the Pauline definition of "perfection" (or "completeness", or "maturity") as a subsequent development of a religious, mystical salvation based on Jesus' death/resurrection. The only common point in those views, perhaps, is that they have nothing in common with the shallow WT concept of "genetic perfection" which is altogether foreign to the Bible.