This is one of the most cliche lines in Christiandom. Especially
when a group or individual is being questioned of it's credibility.
There were many occasions where new-generation churches were
questioned of their doctrines, their followers (as well as leaders)
will use this line as a first line of defense.... but how wrong are
they.
Geneva Study Bible
7:1 Judge not, that ye be not judged.
We ought to find fault with one another, but we must beware we do
not do it without cause, or to seem holier than others or because
of hatred of others.
People's New Testament
Matt 7:1
Judge not, that ye be not judged. The term judge is used in more
than one sense, but Christ's meaning is plain. (1) He does not
prohibit the civil judgment of the courts upon evil doers, for this
is approved throughout the whole Bible. (2) He does not prohibit
the judgment of the church, through its officers, upon those who
walk disorderly, for both he and the apostles have enjoined this.
(3) He does not forbid those private judgments that we are
compelled to form the wrong-doers, for he himself tell us that we
are to judge men by their fruits. (See Mt 7:15-20.) What he designs
to prohibit is rash, uncharitable judgments, a fault-finding
spirit, a disposition to condemn without examination of
charges
Wesley's Notes
7:1 Judge not - any man without full, clear, certain knowledge,
without absolute necessity, without tender love. Luke 6:37.
Matthew Henry Commentaries
7:1-6 We must judge ourselves, and judge of our own acts, but not
make our word a law to everybody. We must not judge rashly, nor
pass judgment upon our brother without any ground. We must not make
the worst of people. Here is a just reproof to those who quarrel
with their brethren for small faults, while they allow themselves
in greater ones. Some sins are as motes, while others are as beams;
some as a gnat, others as a camel. Not that there is any sin
little; if it be a mote, or splinter, it is in the eye; if a gnat,
it is in the throat; both are painful and dangerous, and we cannot
be easy or well till they are got out. That which charity teaches
us to call but a splinter in our brother's eye, true repentance and
godly sorrow will teach us to call a beam in our own. It is as
strange that a man can be in a sinful, miserable condition, and not
be aware of it, as that a man should have a beam in his eye, and
not consider it; but the god of this world blinds their minds. Here
is a good rule for reprovers; first reform thyself.
Source: http://biblecommenter.com/matthew/7-1.htm
See also: http://www.studylight.org/com/bnn/view.cgi?book=mt&chapter=7
If we are allowed to judge on any situation, how then are we to
know what is right and wrong?