https://youtu.be/lv2rEzl7n-o
The devotion is said to be supreme if one surrenders the mind and serves. The devotion shown by the mind that is filled with desires will not yield good results. In fact, devotion in itself a great treasure. It is the best treasure when compared to others. Hence, we must pray to God for the treasure of devotion (bhakthi). When one prays to God with devotion that is mixed with desires and if the desires get fulfilled, then we see people praising God even more and they show much interest on him. In few instances, when the desires are not fulfilled, God is blamed. When we do not understand the favour done by God, we tend to blame God. It is a not a good way. Few people praise in the form of scoldings. They say, "I am serving you since a long time despite undergoing many number of troubles. But, what is the result given by you? You are a God with no mercy." Even though they say so, they do not leave God. They keep on following. Their words might carry good meaning but externally, we listen to only the blaming words. It is not the right path of devotion. 

There is a way in which one has to fulfill the desires. One must behave in such a manner that one earns the mercy of God. We sometimes, demand like Ravana. We must not possess such kind of devotion. It is best to pray, "I do not wish for any desires. Please make my devotion to be steadfast in you." Such devotee will be taken care of by God in the first place.

Once, Vyāsa and Nārada met each other. They were discussing about "What is devotion? Who are mahātmas? How are they like? What is superior?" The discussion moved on liked this - "The planet of Earth is known as karma bhūmi (action based). Any amount of Yogic practices or practices for salvation can be done. On this Earth, all types of atmosphere exist and hence Earth is supreme. Such Earth is floating on the water. Hence, water is superior to Earth. Such water was gulped by sage Agastya with his Yogic power, chanting "Om Keshavaya swaha". With this, we understand that Yoga is much superior to the water. Such great sage Agastya is lying in the sky shining as a star. The sky is so vast. Such vast sky is lying in Lord Vishnu's feet and hence the sky is also known as "Vishnu Pāda". That is why, Vishnu is decided to be the "Uttamōttama Purusha" - the best amongst best! His one foot itself spreads the sky in this manner, then what is it that we can talk about the Vishnu, who is present in each and every atom. Such Mahā Vishnu says that he resides in the hearts of devotees. Hence, the heart of devotee is the greatest. No words can explain about it. Hence, definitely, a devotee is said to be the most superior one. To attain such steadfast devotion, taking the names of God is the first step. To make tens of people do this, bhajans that are sang aloud bring a feel of oneness with God. Devotion helps in broadmindedness. At the very beginning, Tyagaraja, Purandharadāsa, Meera Bai and others sang musical compositions aloud. This will gradually lead to concentration and then the mind attains focus. This is the kingdom of devotion.