This is clearly my opinion on what the meaning of Final Fantasy VII meant. Though opinion, I have enough knowledge on FFVII to justify my thoughts in a sense of a matter that I believe is plausible.
Evidently, we know Final Fantasy VII was not intended to be a love story, but more of a game that delt with real life issues. Love, hate, death and triumph all collide into one with a sort of brilliance and subtle irony. As we see Cloud trying to seek revenge for his mother and hometown, he has to deal with everything in between. And I truly believe that while in the midst of his tragedy, was the reason Aerith was sent to Cloud.
Cloud grew up in an environment full of rejection and disappointments, as he grew to become an adult, Aerith was there to open him up. She made him see that there was more to life than being bitter and being self-centered. Cloud does not know how to express his feelings well, but as we can see, he truly loved Aerith, and she loved him. And they somehow completed eachother. She would have stuck by his side if she hadn't been killed, but perhaps she was always there for him, guiding him.
"How would you say it... Aerith was right there all along. Right by our side."
People say Cloud didn't cry when Aerith died, but I think he did. When he was holding her lifeless body, he mentions his eyes are burning. And unless you've never cried, often times there is a burning sensation before your tears fall. Here in this moment, we see his true emotions for Aerith, that basically said he loved her more than just a friend, and stated all of the things he loved about her.
"Aerith is gone...Aerith will no longer talk, no longer laugh, cry...or get angry..."
One of the most important aspects of Final Fantasy VII, was Aerith's death. And the after results of Cloud's actions undeniably show how he feels. In the wake of her death, I believe it proved that love can remain and last even after it.