If we love Christ we will keep His commandments. So everyday we prove we love Him as we keep His commandments, and His commandments are not burdensome. It is true that we love Him because He first loved us. He has poured out His love within our hearts through His Holy Spirit and we are rooted and grounded in this love. His love does not reside in those who are not His. So if we are truly His we can not help but love Him and it is this love that compels us to no longer live for ourselves, but for Him who died and rose again on our behalf.
We work out that which has been inwrought. We are working out while He is at work in us, and it is this work, this good work, that He has begun that He will complete. But in the middle of all of this is sin. The sin that is present in our members, waging war against the law of our mind. Sin, the great weapon of the enemy which has caused the death of all mankind, which seeks to master us. It is in the battle against sin that our love is proven. The issue is not do we still sin, because we do, but the issue is do we battle against sin, do we strive against sin, are we actively resisting sin. We are to watch and pray that we would not enter into temptation for the spirit is willing, but the flesh is weak.
It is written that those who have been forgiven much love much. Does this mean that those who were more egregious and pervasive in their sin are the ones who love more? No, it means that it is those who see their sin for what it is and understand the depth of their depravity, who, therefore, understand the depth and the riches of the mercy and compassion of God, who then love Him more. This is something that happens as we work out our salvation and grow in Him. Let us, therefore, not think that we have arrived, but realize that we have not, and continue to press on toward the goal of the upward call of God in Christ Jesus.