how do you differentiate this?

Hmm...interesting.

I would say that the first one; "I love you because I need to" shows a false statement of love. I think it means that the person is loving someone only to help themselves. They are saying they are in love to get what they want. The person they "love" is someone that has something they need in life; money, power, etc.

I think the second one; "I need you because I love you" is the statement that shows a real sense of love. The person who says this doesn't want power or wealth...they want love. They want the person they are with, and would sacrifice everything to be with them.

i think i have answered this in the past but i will reply anyway

"i love you because i need you"
applies mostly to a relationship that is based on material only, i think it is common to those who decide that they are done with being poor or lacking material stuff and decide that he/she will just accept someone who will be able to provide her/him with all the material stuff he dreamed of in life.
i dont think it is wrong or right.
we only live once and as long as we are not harming someone and if the person being used accepts this fact then that is great for both of them BUT if it's not then i feel it is not fair to the "victim"

"i need you because i love you"
reflects that there is TRUE, PURE and REAL love in this world.
i am happy that i belong to this group and i can honestly say that i am very happy and grateful that i have found a man who completes me and makes me whole and i ALWAYS need him as my love or my world will never gonna be the same if he is not there.

takecare!

loving someone because you need them isnt really love its called being co-dependent and your just claiming to love the person because you dont know how to life your own life without the things that offer you. The second part sounds about right I need to have the people I love close to me because Ive made them a part of who I am but at the same time I love them enough to let them go if that is whats best for them

I would rather hear, I need you because I love you, not the other way around.. I would rather have someone love me than just have someone need me.. You can need someone without the love, but you can't love someone without needing them.. Did I mess your mind up, I did mine.. Have a great evening..