16.25 [Grammar note: the word for "the one who is able" is a substantive participle.]
16.26 This sentence is very complex grammatically, in that there really is not indicative verb in these three sentences!
16.27 One thing worth mentioning here is that the English hides the fact that the word "eternal" or "ages" is used three times, once in each verse here. Things have been hidden for ages; God has given an eternal command; and now God is in glory forever.
An ironic twist of the Bible that Romans ends with the wisdom and glory of God...which Paul will take up in the first page of 1st Corinthians in a very different way!