The motivation of love is 100% more powerful and effective than the motivation of fear or hate. It also has positive long term effects. The majority of my life was lived out of fear: fear of punishment, fear of rejection, or fear of failure. I look at the growth I experienced during the first couple decades of my life and see that although I was a Christian since a very young age, it was a very slow growing process. In the last few years though, since God began setting me free of many negative mindsets, I've had an entirely different experience.
With a motivation of love, I am finding that my growth in Christ keeps increasing in leaps and bounds compared to my past. My life has completely turned around because I am desiring to please God rather than doing something because I'm afraid of what He'll say or do if I don't.
This principle applies to every aspect of my life. In a practical sense, if I am desiring to live a healthy lifestyle, I'm not going to get very far if my primary motivation is hate for the body I have now or fear of what I'll become if I don't change things around. However, if I eat healthy and exercise because I love myself (no, not in a proud way, but loving the work that God has made), then I am more likely to continue making good choices in how I take care of myself.
Same goes for relationships. If I'm lonely and afraid of being alone for the rest of my life, my motivation for dating someone is not very good. Entering a relationship because of this motivation will most likely produce an unhealthy relationship. I want my motivation for dating/getting married to be because I feel God's blessing on it and that together with this man, we can be stronger in Christ than we could be apart.