Thanksgiving is the greatest of all prayers

Let all things be done for the glory of God and in all things give thanks.
Everything that is, that was and ever shall be, exists because of God.

God pours out good things upon the lives of the just and unjust alike and He abounds with acts of kindness towards us all.

Brethren, there are three different responses to an act of kindness done by God;
  thanksgiving,
  silence
  or grumbling and complaining.

Thanksgiving is holy and pure and delights our God.
Thanksgiving is the greatest of all prayers that we can render to God.

Silence is golden.
Of the ten lepers that Jesus healed, only one returned to give thanks.

But complaining and grumbling is returning evil for good.
That makes it the worst of all prayers.