'Acknowledged' in the Bible

just as you have [already] partially understood us, [and one day will recognize] that you can be proud of us just as we are of you, in the day of our Lord Jesus.

it is He who has also put His seal on us [that is, He has appropriated us and certified us as His] and has given us the [Holy] Spirit in our hearts as a pledge [like a security deposit to guarantee the fulfillment of His promise of eternal life].