True encouragement is truth. It can only be from God or those He speaks through.
Flattery can come from anyone other than God but encouraging truth (and all truth is encouraging) only comes from God.
Flattery’s goal is to get something from you. Encouragement’s goal is to teach and lift up with truth support. The former is selfish and worthless and the latter is selfless and priceless. 😃❤
Romans 1:12 “that is, that you and I may be mutually encouraged by each other’s faith.”
2 Corinthians 13:11 “Finally, brothers and sisters, rejoice! Strive for full restoration, encourage one another, be of one mind, live in peace. And the God of love and peace will be with you.”