Matthew 15:14

Leave them alone. They are blind guides! But if one blind man leads another, they will both fall into the ditch!"

Luke 6:39

And he used a figure saying, "Can one blind man lead another? Will they not both fall into a hole?

Matthew 23:16-24

Alas for you, you blind guides, who say, 'If anyone swears by the sanctuary, it does not matter, but if anyone swears by the gold of the sanctuary, it is binding.'

1 Timothy 6:5

and mutual irritation between people of depraved minds, who are lost to the truth and think of religion only as a means of gain.

2 Peter 2:1

There were false prophets too among the people, just as there will be false teachers among you, who will introduce destructive sects and deny the Master who has bought them, thus bringing on themselves swift destruction.

2 Peter 2:17

Such men are dried-up springs, clouds driven before the storm, and they are doomed to utter darkness.

Revelation 19:20

And the animal was captured and with it the false prophet who performed wonders on its behalf by means of which he led astray those who had let the animal's mark be put on them and who worshiped its statue. Both of them were flung alive into the fiery lake of burning brimstone.

Revelation 22:15

The dogs, those who practice magic or immorality, murderers, idolaters, and anyone who loves falsehood or tells lies will be shut out of it.

Treasury of Scripture Knowledge

Summary

Let them alone: they be blind leaders of the blind. And if the blind lead the blind, both shall fall into the ditch.

Bible References

Let

1 Timothy 6:5
and mutual irritation between people of depraved minds, who are lost to the truth and think of religion only as a means of gain.

They

Matthew 23:16
Alas for you, you blind guides, who say, 'If anyone swears by the sanctuary, it does not matter, but if anyone swears by the gold of the sanctuary, it is binding.'
Luke 6:39
And he used a figure saying, "Can one blind man lead another? Will they not both fall into a hole?

And if

2 Peter 2:1
There were false prophets too among the people, just as there will be false teachers among you, who will introduce destructive sects and deny the Master who has bought them, thus bringing on themselves swift destruction.
Revelation 19:20
And the animal was captured and with it the false prophet who performed wonders on its behalf by means of which he led astray those who had let the animal's mark be put on them and who worshiped its statue. Both of them were flung alive into the fiery lake of burning brimstone.
Revelation 22:15
The dogs, those who practice magic or immorality, murderers, idolaters, and anyone who loves falsehood or tells lies will be shut out of it.

General references

Mark 8:13
And he left them and got into the boat again and crossed to the other side.
Luke 12:57
Why do you not decide what is right yourselves?
Luke 20:8
And Jesus said to them, "Nor will I tell you what authority I have for doing as I do."
1 Corinthians 14:38
If anyone pays no attention to it, pay no attention to him.