In Judges 16:15 Delilah pointed out that the failure to love in action was a heart problem. I know that is the problem I have. There is something in the way I think or the way I feel that often keeps me from having that commited will to act lovingly in the moment.
Jesus put it this way, "But the things that proceed out of the mouth come from the heart, and those defile the man. For out of the heart come evil thoughts, murders, adulteries, fornications, thefts, false witnesses, slanders. These are the things which defile the man. I can readily admit that I have at least had thoughts of all of these sins. It shows me that there is something wretched and vile within me. As Jesus says, I'm defiled.
Meditating on that for awhile is a real eye opener. I have really stopped being amazed at how often evil thoughts or impulses arise. Yet, I also know that the Gospel gives us hope. I am not given the impression anywhere in Scripture that I just have to consign myself to a life of defeat and depression over continually being plagued by and falling to sin. That would be antithetical to the Gospel.
The Gospel offers hope to sinners. And that hope is not just justification and forgiveness of sin. I know that in more defeated times of my life I certainly have found comfort in the doctrine of justification; and what Christ has done for me is certainly motivation to live for Him. But I find that the Gospel also holds out hope for real change in this life as well.
The Bible speaks of transformation. 2 Cor 3:18 says, "But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit."
This verse indicates that as I gaze into the glory of Christ I am continually being transformed into Christlikeness. This is the ultimate goal of the believer in regards to change, to be like Christ in heart and thus, speech and action--love.
Paul tells us that he has confidence that God will carry this work on to completion (Phil 1:6). So, we can be sure that God is changing us and that we can change.
I know also that God has given us His Spirit to enable us to manifest this Christlikeness and produce love (Gal 5:22-23). What must change then is our hearts. By the Spirit the heart must be controlled, made gentle, faithful, good, kind, patient, peaceful, joyful, and loving.
The process of change is called repentance. More on that later.