It took me some time even after I got saved to realize the full truth about God's love and grace. Having the assurance of my salvation has given me an attitude of gratitude towards by Lord and Savior and the thought of ever intentionally sinning against Him is repulsive. It is no longer fear that gives me the desire to be holy but love. I see the process He has worked in me conforming into the image of Christ and that is how I know I am His own. It is something I will never give up - nor ever want to.
It's the same for me too. I now try to be the best I can be out of love for Our Lord who saved me when I certainly didn't deserve it. I no longer conform out of fear but intense LOVE of my Father.