John Piper, God is the Gospel:
Gratitude that is pleasing to God is not first a delight in the benefits God gives (though that will be part of it). True gratitude must be rooted in something else that comes first — namely, a delight int he beauty and excellency of God’s character. If this is not the foundation of our gratitude, then it is not above what the “natural man,” apart from the Spirit and the new nature in Christ, experiences. In that case, “gratitude” to God is no more pleasing to God than all the other emotions that unbelievers have without delighting in Him.
Words of Grace 