All Religion Are The Philosophy Of Love. Can You Prove It?

To begin, love is something that is felt and experienced - not proven.
Generally speaking religions uphold a set of rules, standards, guidelines, etc. They are in place to uphold the religious followers who are perceived to be doing something wrong or against G-d. In that way, the rules themselves are set in place with an intention to assist the followers but they may not be with a loving intention. Whether the rules will actually work and the outcome is a wholesome outcome is yet to be seen.
When a religion teachers that followers of another religion are wrong - that in itself is not an act based on love, it's a thought with an intention that is inciteful and may lead to war. In that way ALL religions are not based on a philosophy of love.
In the ways that most religions want what's best for their followers, and wants them to have more light and love in their lives, value life - not harm others, be knowledgeable, evolve spiritually, and take actions to uplift each other in our life journey... Those philosophies are "of love".
I don't know anyone who knows the philosophies of ALL religions. I doubt that what you ask can be proven - however, generally speaking I believe that many religions are based on loving intentions for humanity.
And, each religion does it a different way. It's not a matter of proving which is right and which is wrong. If we want to personally move forward as a part of a  healthy humanity, we need to understand more, open our hearts to other ideas and accept the differences while we set a personal example of excellence.

The religion that is based on love in a persons heart that extends to all of humanity - that is a religion that is based on a philosophy of love.