Warm Fuzzies

It's true that the Bible sometimes seems to portray marriage in terms of a business transaction. Nevertheless, in many cases whatever business takes place is secondary to the motivations to marry. There are many examples of people who marry for looks, or because the spouse passed some test, or because they were in love. Now, not every marriage is extolled in the Bible, but one significant good one based on love was that between Jacob and Rachel (Gen. 29:18-21).

Of course, the New Testament also teaches the necessity of love in marriage (Eph. 5:28,33), and you have already mentioned the Song of Solomon, which is nothing if not packed with the "warm fuzzies" -- it's downright "steamy". Of course, the greatest model of the ideal marriage is God's relationship to his people, and the Bible continually uses the language of love to describe this relationship.

[The rest of this response is more geared toward actual feelings and practice, not biblical data, and this isn't really my field. I can offer a few insights, but I recommend you prefer over my comments the advice of someone who knows a bit more than me about these kinds of things, and a lot more about you (a Christian counselor, a trusted mentor, a parent, etc.).]

This is not to say that every "butterfly" is true love. Some butterflies are mostly fear/adventure, while others are mostly lust. And even true-love butterflies don't last forever, even though true love might. Nevertheless, butterflies can be a good indication of your feelings for another person. Still, I would count emotional attachment as more important than the physical response of butterflies. In my experience, butterflies more often than not indicate adrenaline and/or nervous excitement. The more comfortable you get with someone, however, the less nervous you feel and therefore the fewer butterflies you feel. If what really charges your battery is the adrenal feeling of butterflies, then you probably aren't ready for marriage. I would tentatively suggest that a more signficant issue is feeling that you genuinely love someone, that the person is an important part of you, and that the person is the type with whom God would have you spend your life.

You also asked: "What if someone is courting, and the 'feelings' start to fade? Is that an indication of God's will?" To this I must respond that everything is in some way or another an indication of God's will, but learning how things indicate his will requires great wisdom. I do not feel competent to the task of answering this question pointedly, especially not in a universally applicable way. One of the most difficult aspects of the question is "What is God's will?" His will for one person is not necessarily his will for every person, and relationships are as varied as the people who get involved in relationships. Advice on love and marriage is not a one-size-fits-all matter. Instead, this is the kind of question you need to ask of someone who knows you really well.

For a wiser, more insightful answer than mine, I feel comfortable recommending the book Discovering God's Will by Sinclair Ferguson. It's a great little book, and includes a chapter on finding a spouse.