Romans 16:18

Turn away from them. For men of that stamp are not the slaves of Christ, but are slaves to their own appetites. By their smooth and fair speech they beguile the hearts of the innocent.

James 1:8

double-minded as he is, unstable at every turn.

1 Thessalonians 2:5

For as you well know, I never resorted to flattery, nor to any pretext for enriching myself. God is my witness!

Treasury of Scripture Knowledge

Summary

They speak vanity every one with his neighbour: with flattering lips and with a double heart do they speak.

General references

Bible References

Flattering

Romans 16:18
Turn away from them. For men of that stamp are not the slaves of Christ, but are slaves to their own appetites. By their smooth and fair speech they beguile the hearts of the innocent.
1 Thessalonians 2:5
For as you well know, I never resorted to flattery, nor to any pretext for enriching myself. God is my witness!

General references

Acts 12:22
"The voice of a god, and not of a man," the people kept shouting.