Matthew 15:14

"Let them alone. They are blind men leading the blind; and if one blind man leads another, both of them will fall into a ditch."

Luke 6:39

He also told them a parable. "Can a blind man lead a blind man? Will they not both fall into a pit?

Matthew 23:16-24

"Woe unto you, blind guides, who say, If any one swears by the Sanctuary, it is nothing, but if any one swears by the gold of the Sanctuary, the oath is binding.

1 Timothy 6:5

and wrangling between men whose minds are corrupt and destitute of the truth; who suppose that godliness is a source of gain.

2 Peter 2:1

But there were false prophets, too, among the people, just as among you also there will be false teachers. These will secretly bring in destructive sects, denying even the Master who bought them, and bringing swift ruin upon themselves.

2 Peter 2:17

Such men are like waterless springs, or mists storm-driven; for them the blackness of darkness has been reserved.

Revelation 19:20

And the beast was seized, and with him the false prophet who performed miracles in his presence to deceive those who had received the brand of the beast, and those who worshiped his image. The two were thrown alive into the lake of fire, blazing with brimstone.

Revelation 22:15

Without are the dogs, the sorcerers, the immoral, the murderers, the idolaters, and all who live and make a lie.

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 wrangling between men whose minds are corrupt and destitute of the truth; who suppose that godliness is a source of gain.

They

Matthew 23:16
"Woe unto you, blind guides, who say, If any one swears by the Sanctuary, it is nothing, but if any one swears by the gold of the Sanctuary, the oath is binding.
Luke 6:39
He also told them a parable. "Can a blind man lead a blind man? Will they not both fall into a pit?

And if

2 Peter 2:1
But there were false prophets, too, among the people, just as among you also there will be false teachers. These will secretly bring in destructive sects, denying even the Master who bought them, and bringing swift ruin upon themselves.
Revelation 19:20
And the beast was seized, and with him the false prophet who performed miracles in his presence to deceive those who had received the brand of the beast, and those who worshiped his image. The two were thrown alive into the lake of fire, blazing with brimstone.
Revelation 22:15
Without are the dogs, the sorcerers, the immoral, the murderers, the idolaters, and all who live and make a lie.

General references

Mark 8:13
Then he left them, and getting into the boat again, went away to the other side,
Luke 12:57
"And why do you not, even yourselves, judge what is right?
Luke 20:8
"Nor will I tell you," Jesus answered, "by whose authority I do these things."
1 Corinthians 14:38
But if any one disregard it he will be disregarded.