Objectively Speaking

καὶ αὕτη ἐστὶν ἡ μαρτυρία ὅτι ζωὴν αἰώνιον ἔδωκεν ἡμῖν ὁ θεός καὶ αὕτη ἡ ζωὴ ἐν τῷ υἱῷ αὐτοῦ ἐστιν

We might translate,
"And this is the testimony, that God gave us eternal life, and this life is in his son."

I was reviewing the midterm with a student on Saturday and one of the questions was a true or false about this verse in 1 John 5:11. The student had answered "true" to the question, "Is υἱῷ the indirect object?" ( I may not have the question exactly right)

I thought, "Well, its obviously in the dative case, so, yes, it must be the indirect object," but it had been marked wrong. I was at a loss to explain, and thought, well I would surely have gotten that question wrong if I had taken the test.

Then, somewhere from the deep recesses of my memory I recalled Jim saying that the dative case can be used for the indirect object AND for the object of a preposition. That is the situation we have here and it is a good example to remember. (seems I remember mistakes more than correct answers)

Perhaps that was the object of the question...