Romans 16:18

For such are not servants to our Lord Jesus Christ, but to their own belly; and by smooth speeches and flattering commendations deceive the hearts of the guileless.

James 1:8

A double-minded man is unsteady in all his ways.

1 Thessalonians 2:5

For neither at any time used we insinuating language, as ye know, nor a pretext for covetousness; God is 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
For such are not servants to our Lord Jesus Christ, but to their own belly; and by smooth speeches and flattering commendations deceive the hearts of the guileless.
1 Thessalonians 2:5
For neither at any time used we insinuating language, as ye know, nor a pretext for covetousness; God is witness:

General references

Acts 12:22
And the populace shouted, It is the voice of a god, and not a man.