1 Corinthians 1:5

That in every thing ye are enriched by him, in all utterance, and in all knowledge (KJV)

Then: Called in the past, the Corinthians are so enriched in the present they are both knowledgeable and able to tell others about Christ. This is a gift based on grace for which one can be truly thankful. N. T. Wright (p.4) believes the verse indicates great ability for these believers to teach one another and in doing so, strengthen and confirm each others faith. Dr. Magness considers the enrichment, calling, and Christ's confirmation to be a "past" event in the believer's life, even though it allows for a present action. Wesley notes a hidden meaning mixed in with Paul's thankfulness. In referring to "knowlege" and "utterance," Paul picks out two attributes and skills greatly admired in and by the liberal Corinthians. Honored by Paul's indirect praise, they are later more willing to understand why these gifts must be both channeled and utilized in glorifying God, not themselves. Serving the Lord well is their unending goal.

Now: Serving the Lord well is our unending goal. By elevating thankfulness to a top priority, today's believers learn much. Being thankful for the knowledge and ability to tell others about our experiences puts a right priority on the values of teaching one another, strengthening one another and confirming one another. Unfortunately, being Corinthian comes just as naturally as in New Testament times. Proud of church heritage, proud of knowledge, proud of skills, there we stand oblivious to the blight and disease of pride growing on what were meant to be wonderful gifts. Thanksgiving can strip away the fungus, cut out the spots, and let God's grace shine through again.
Added source: Wesley's Notes on the Bible http://www.ccel.org/ccel/wesley/notes.i.viii.ii.html