I'm pretty sure this is a very unpopular opinion that I have but I actually feel like respect is more important because; I think you should respect everyone and their differences, I don't think you "need" to love everyone.

Love is nice, and when we talk about the world and every human being and every country I definitely think we should love each other, but for me personally I don't really feel like I need to be "loved" and love others, love is a strong emotion and I'm more than satisfied if the people around are nice, if I like them and have fun being around them then that's more than enough for me! But that is just me.

I'm sorry if some of it doesn't make much sense to you xD

I don't think you can have love without respect. At least not healthy love.

Both is really the best answer, but I just feel like it's too obvious and also that no one will choose respect while a lot will choose love.

Here is my opinion in more detail though:

For humanity: Both!
For me personally: Respect