Verse 2.51: By thus engaging in devotional service to the Lord, great sages or devotees free themselves from the results of work in the material world. In this way they become free from the cycle of birth and death and attain the state beyond all miseries [by going back to Godhead].
The word devotion may bring up all types of images and feelings. In the context of bhakti yoga, devotion means love in action. Not only does one experience emotion towards God, but one expresses it by their behaviour, thoughts and actions.
Mere sentimentality is not enough though. Love needs to be expressed and demonstrated. The Lord is a person who also has feelings and emotions and so just saying, "I love you" and then forgetting about the Supreme doesn't really mean much. Think of someone you really love and are really close to. Do you just simply say "I love you" and do nothing else for them? No way! We do everything in our capacity to serve and please the ones' we love.
The thing is, most of us have forgotten that we love God. Some might even say, "Hey wait a minute, I'm not even sure I believe in God." But that's like saying, "I don't believe there's such a thing as a billion dollars." When asked why, the person might respond "Because I've never seen it or because I don't have it." But those who have a billion dollars definitely know that it exists. It's just a matter of being exposed to it.
Similarly, we may not have been exposed to the knowledge that we ourselves are spiritual and are parts and parcels of God. That's right! We're qualitatively one and the same (i.e. we are spiritual) but quantitatively different. Prabhupada, our master bhakti teacher, illustrates the point by giving a very apt analogy of a gold fleck and the gold mine. The fleck is non-different from the gold mine since it is made of the same element, but quantitatively there's a huge difference.
That's why we can never be God. The position is already taken. But because we are part and parcel of the Lord, the way we can be eternally happy is by making him happy. That formula is being shared here.
See, some of us may not be at that stage where we love God with all our heart and being. We might just be beginning to reconnect and recognize our connection with him (like me). That's why God (who has numerous names including Krsna), is giving us an easy yogic process. By performing our work in a spirit of acknowledgement that all our talents and resources are blessings, we express our gratitude by offering whatever results that come to him. In this way, we become free of karma. We don't need to totally change our life, give up everything and go to the forest. Just by cultivating this attitude of gratitude, we begin to start developing real feelings towards God and see the manifestation of grace in our lives.
By doing this, the day will come where we won't just practice bhakti yoga anymore...instead, we will live a life of bhakti and devotion.