1 Corinthians 4:4

for, although I am not conscious of having anything against me, that does not clear me. It is the Lord who cross-questions me on the matter.

James 3:2

We all make many a slip, but whoever avoids slips of speech is a perfect man; he can bridle the whole of the body as well as the tongue.

1 John 1:8-10

If we say, 'We are not guilty,' we are deceiving ourselves and the truth is not in us;

Treasury of Scripture Knowledge

Summary

Who can say, I have made my heart clean, I am pure from my sin?

Bible References

General references

1 Corinthians 4:4
for, although I am not conscious of having anything against me, that does not clear me. It is the Lord who cross-questions me on the matter.
James 3:2
We all make many a slip, but whoever avoids slips of speech is a perfect man; he can bridle the whole of the body as well as the tongue.
1 John 1:8
If we say, 'We are not guilty,' we are deceiving ourselves and the truth is not in us;