Can Old Lovers be Just Friends?

Hey! It's me again. I've been busy researching for my book. It's so many angles to take that i don't know which one to go. Pray that I open my eyes and my heart to what God wants me to write.
The research for my book has also been teaching me a lot of things about myself. I've been dating the same guy off and on for the past three years. We've had some ups and downs and he's been very supportive of me since I decided to give my heart to Christ. I still have major feelings for him, but he's not saved. He's seeking, but he's just hasn't taken that one leap of faith. So, after a lot of soul searching and talking (to God and him), we decided to be friends. He asked me to go out with him next weekend and i said i didn't know if we should because its too soonand i still love him. i prayed about it and discussed it with friends. Some of them were helpful. Others gave superficial advice. Then i decided to go because after all we've been through together( and we've been to hell and back- literally life and death) i do value him as a best friend. And maybe i can lead by example. But my question to you all is: CAN OLD LOVERS BE FRIENDS?
All comments are welcome, but i would prefer Christian perspectives.

What did i learn about myself while researching for my book? That i wrestle with God for control and i struggle everyday to submit my ways to His will. Any advice.