A very good book to read on how to tell its love and not just lust is this book :
Finding a Lasting Love: Friendship, Romance, Commitment: Dick Purnell: 9780736910804: Amazon.com: Books . Get a used copy for $.01 plus shipping.
Typically, here is the order of things happening :
1. You meet someone for the first time and have some conversation.
2. After this initial meeting and more meetings, you can see that you have alot in common and a 'connection' is starting to take place based on getting along good when you are together .
3. During this process thus far, you (or both of you) find the Other physically appealing to some degree and because you have connected emotionally , the ENTIRE PERSON including their physical attributes are appealing to you. For the male, his sexuality is heightened when he looks at her because he is wired by God with an apparatus which is stimulated by the shape of a females body. For the female, she may or may not feel the same way physically...but more often than not, her focus will be on the INNER person that you portray and will include honesty, sensitivity, attentiveness, validating her responses, kindness, and comfortability being around you.
4. As time goes on and your friendship deepens, there typically occurs a sense of 'OWNERSHIP' ...that is... you want to become more of an Item than keep it where its been thus far. This is typically a time when sexuality starts kicking into high gear for both of you with the fueling attributes i mentioned above already... and its going to be very important and necessary to stay within the sexual boundaries that God has setup for you both. These are for your own good and hers, plus, not to harm your personal relationship with God (because it shall if you become uncontrolled and lax) .
Essentially, that is the fundamental process of what takes place with Lust. WHere real LOVE comes into play, is when alot of time has passed spending valued time together / shared experiences / shared secrets / shared respect / etc... and...when you get to the point where you conclude that your life would be severely at a loss if that other person were suddenly no longer a part of the equation. Its when you KNOW you have graduated beyond the Lust Stage and you start thinking lifelong commitment because what this person has come to mean to you. You know its genuine because you havent rushed the feelings, situation, commitment , or placed stress on the Other (or Yourself) to hurriedly move the relationship faster than what it should go -- you have allowed it to naturally take its course and it has ended up in a deep profound Love which is backed up by solid commitment and a lifelong desire to never be seperated again. Most of all, you have constantly ran the entire process thru Gods loving filter, and you know that you know you have recieved Gods will and blessing to move it to the final step of a marriage in his presence and for his glory as a lifelong Union.
Did that help you any ?