1 John 2:21

I have not written to you, as to people unacquainted with the truth of the gospel: but as to such who know it, and know that it cannot give rise to any imposture.

2 Peter 1:12

for this reason I shall never omit to put you in mind of these things, however knowing you are already, and settled in the truth.

Romans 15:14-15

As to myself, I am persuaded, my brethren, that you abound in goodness, and in variety of knowledge, and are able to instruct one another.

Jude 1:5

Now, I would call to your remembrance what you once were inform'd of, that when the Lord had delivered the people from the land of Egypt, he afterward destroyed those that were disobedient.

Treasury of Scripture Knowledge

Summary

I have not written unto you because ye know not the truth, but because ye know it, and that no lie is of the truth.

Because ye know not

General references

Bible References

Because ye know not

Romans 15:14
As to myself, I am persuaded, my brethren, that you abound in goodness, and in variety of knowledge, and are able to instruct one another.
2 Peter 1:12
for this reason I shall never omit to put you in mind of these things, however knowing you are already, and settled in the truth.

General references

John 10:5
a stranger they will not follow, but flee from him: for they know not the voice of strangers.