Depends on the context of the dialog, but it would basically be that there's as much evidence to support that comment than there is that god even exists.

Laugh in their face. I know rather rude. Depending on how close (emotionally) that person is to me, I would try to discuss it with them or just blow it off.

What do gods have to do with it?

I would laugh and say, that is one of the most ridiculous comments I have ever heard, and laugh again.

Delusional

Imagine the face of a Neanderthal mother (who couldn't produce language due biological disadvantage) carrying a newborn and obviously caring for that newborn when she understands what that IgnorAnus preacher is bullshitting! Love was (attempted to get) killed by 'God' (s), so many times!

I wouldn't.

I wish that I could give you an answer that would help, but responding to a religious belief that has been programmed into a preacher or a church member is like having a conversation with a bot. You can’t make a believer THINK. That is something that they have to choose to do for themselves. You know how you define love and know what you feel when you tell someone that you love them and that is all that matters. You don’t need to be like the Preacher and convince him that his experience with love needs to be like yours. He on the other hand has a pathological need to convince other people that his definitions of love and life are the only ones acceptable because that is how he gets to keep influence over people. His only power is in convincing folks that he speaks for an entity who does not exist.

I wouldn’t in that situation, but in a one on one with a friend I would assure them that I can and do

You can’t have true love for people WITH GOD. One or the other

Firstly can I say I feel for your situation having never had the problem of having to pretend to believe. My response would probably be to point out to the all the horrific things done in the name of a god, all of the passages in the bible that talk about doing horrific things to people and ask them how they could love if they believe in a god.

"How would you respond to "You can't have true love without God"?
Utter Bollocks.

Ask them back if they love or are loving, they have to say, yes. Then you say. And are you truly loving ? They say yes. And than you say. That proves then that you can love without god, since you love and I am sure that your god does not exist, and I can observe the actions of love but not god.

It is near to a circular and presuppositional argument, but it is not quite, and since theists are fond of those sort of arguments, it is fun to throw one back and watch them puzzling. (Make it plain that the god you are talking about is just their theist god, which can be disproved, and not any vague deist god, which you can't.)

Ugh?

If the preacher is of the "religious right" type, they have promoted an immense amount of hatred, racism, & intolerance. This attitude is not love

The preacher may have a not so hidden agenda to "sell" god. Who is he to tell you can't love people without dragging in the god myth. In history, the god myth has caused more hate than love--religious wars, pogroms, inquisitions, crusades. It has led to much violence & horror.It has fostered intolerance & much injustice.

Love is the feeling you have for other people, or perhaps other things, your country, your dog, your ideas. It depends on the relationship you have with these other entities, who you are & who or what you believe they are. You can "love" god, but you are in love with an idea. Ideas are not necessarily real.

Who is this preacher to say your love isn't "real". Love is like pain. Only you can determine if you have it, not anyone else. I would respond by voting with my feet & walking out of this clown's church. Maybe you want to come out of the closet to your friends & relatives, or maybe not, but you have a right to your own perceptions

idiot

It depends on the type of love being referred to, which I can't know without context.

If he means the kind of love one feels for another intimately, then it is self evident that this isn't true because plenty of people have found this without god, and just pointing to a single example debunks this claim.

If he means the type of love felt between a tightly bound community, for which empathy and trust are the main drivers of unity, then you only need to point to all the godless countries and societies that currently exist in the world.

The last possibility is that he means the love one feels for a god, and this I can't refute because you must assume that a god exists before you can love him, so obviously you can love an entity that you have never seen or interacted with.