In life there are firstly five realities:
There is you – each and every one of us (in fact each and every thing) is a composite.
We have a body (which both limits and expresses) and we have who we Are – an infinite, intangible Soul (feelings, senses, with intellectual, emotional, verbal abilities.)
All souls desire Love.
Love is the feeling you have when you and another unite.
All souls desire self-determination (so while we love love, we hate feeling coerced.)
As such for love – unity (Union) to work, two need to know how to unite.
As such, the prerequisite for marriage – apart of course that as God too is (an undefined unlimited) soul, hence desires both your love, the love of who you love, and the love between you (a good example is parents towards (and between) their children) and as God knows, what is best – both parties must be fundamentally committed) – so getting back to creating and more importantly sustaining unity:
A. A person must have inner strength (if we are passive (or aggressive as apposed to assertive…)
B. A person must fundamentally be seeking a. To fulfill the Divine reason, purpose, mission (as both encapsulated in Torah and Mitzvos /, as well as the Rebbe (primarily, including the Rebbe’s call to have a Mashpia (as this is the only way to beat our internal Yetzer Hara (evil, hence biased, hence rationalizations of evil) b. We Must Never Seek In Marriage Anything But Unity.