If you think Christians should not judge others, then this section is for you.
If you think the Bible forbids judging others, then you haven't read it. The Bible forbids superficial judgment based on appearances and it forbids hypocrisy, but it does not forbid judgment. On the contrary, the saved are commanded to pass judgment on others.
Lev 19:15 In righteousness shalt thou judge thy neighbour.
Jn 7:24 Judge not according to the appearance, but judge righteous judgment.
I Cor 2:15 But he that is spiritual judgeth all things, yet he himself is judged of no man.
I Cor 5:12-13 For what have I to do to judge them also that are without? do not ye judge them that are within? But them that are without God judgeth. Therefore put away from among yourselves that wicked person.
I Cor 6:2-3 Do ye not know that the saints shall judge the world? and if the world shall be judged by you, are ye unworthy to judge the smallest matters? Know ye not that we shall judge angels? how much more things that pertain to this life?
Liberal Christians frequently take Matthew 7:1 out of context by claiming that it is prohibition against judging others. The full context is Matthew 7:1-5, and it is a prohibition against hypocrisy.
1 Judge not, that ye be not judged.
2 For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again.
3 And why beholdest thou the mote that is in thy brother's eye, but considerest not the beam that is in thine own eye?
4 Or how wilt thou say to thy brother, Let me pull out the mote out of thine eye; and, behold, a beam is in thine own eye?
5 Thou hypocrite, first cast out the beam out of thine own eye; and then shalt thou see clearly to cast out the mote out of thy brother's eye.
My job as a Pastor is to find folks who are lost and to try to get them saved. That job would be made a lot harder if I were unable to judge who is lost and in need of salvation.