Out of love, he wanted to show his love and his glory.
"Father, I want those you have given me to be with me where I am, and to see my glory, the glory you have given me because you loved me before the creation of the world." (John 17:24)
I have no idea how you reconcile that idea with him supposedly setting up a world where those who essentially don't love him go to eternal punishment without remission (or even at a pinch suffering for 'ages' (aions)) but I guess that's your bag.
I'm guessing that you simply don't believe that. Which again, is your bag. I guess you might be playing down the retribution and the harshness of the punishments in the bible and believing that they are corruptions of 'real, original' christianity (in the case of the usage of hell in the NT) or somehow justified in the case of the OT God when it came to running swords through the bellies of pregnant non-believers etc.
But even then, it doesn't square up for me. First, I think there's probably too much pick 'n mix and rose-coloured spectacles going on vis-a-vis how a bunch of eastern mediterranean and middle-eastern theists really viewed the world way back then and what their conception of justice actually was, and second, I've helped bring up two little creations of my own, and something about even the mild version of the arrangement that you might believe in doesn't smell right to me. I would never, for instance, have punished them, in any way, for not loving me back, even if it hurt me when they didn't. In a nutshell, I think insisting that they love me would not be justified, since imo they should be free to choose not to if that is what they want and what makes them happy. I made them. I don't own them.
Now, you might say that in many cases, loving one's parents will tend to make a child happy, but it isn't always the case (and I might ask why would it
have to be that way). And anyway, 'love me or you'll suffer' or even 'you need to love me to be truly happy', if it's an arrangement I set up from the get-go, well, I'd surely have to admit that I wasn't compelled to set it up that one particular way. I could, if I'd wanted, have created a world where there was no suffering at all (and no need for it as a pre-requisite to appreciating happiness) or at the very least no suffering specifically for not loving me back.
I know you'll have an answer, and my guess is it'll be well-intentioned, but I also guess that I'll be scratching my head afterwards, because I will think that (a) it's flawed and (b) it's probably a wonderful delusion, the product of the minds of humans, many of whom are/were pretty well-intentioned also.