This personal revelation of a direct communication with God Himself by Kay Warren appears at Christianity Today online here:

After the service [Kay and Rick Warren] walked back to the campus and went into a prayer room to pray together; the tone of the evening had been far different from that of the first date. As they finished praying, Rick looked up at her and blurted out, “Will you marry me?”

The proposal, as sudden as it was, did not come as a complete surprise to Kay. The mere fact that he had asked her out signaled that he had serious intentions. Still, she was not prepared for it, not that soon, and her mind raced to come up with an answer. “I instantly said to God, ‘Okay, God, I don’t love him. I’m in love with his best friend. What in the world do I say to this guy who has asked me to marry him?’ And God clearly said to me, ‘Say yes, and I’ll bring the feelings.’ So I said yes.” They kissed for the first time.