I would like to share this Excerpts from: Sathya Sai Baba, Divine Discourse "Let Unity Be the Undercurrent Everywhere" 2 Mar 2003 regarding 9 types of devotion.
What are in details the 9 Bhakti and where they come from (sources)?
Nine forms of devotion, joy and sorrow
You may follow any one or all the nine forms of devotion like Sravanam (listening), Kirtanam (singing), Vishnusmaranam (contemplating on Vishnu), Padasevanam (serving His Lotus Feet), Vandanam (salutation), Archanam (worship), Dasyam (servitude), Sneham (friendship), Atmanivedanam (Self-surrender). More than following any or all the nine forms of devotion, it is the inner feeling or motive behind the forms of Bhakti that is important. Your inner feeling must always be pure. Of all the nine forms of devotion, Sneha (friendship) is the most important. It is only when you cultivate this feeling of friendship with God, you can reach the last stage of Atmanivedanam (self-surrender). For this purpose, you must have a pure heart, which in turn is based on love and devotion. You must have pure and selfless love towards one and all. Such love is not a one-way traffic. Today, we are prepared to receive love from all people, but are hesitant to share our love with others. It should be a give and take policy. Love begets Love. You must also be prepared to receive love from others. Love is a gift of God. In fact, you must rise to such a level that whatever is given by God, you must be prepared to receive wholeheartedly. At times, God also gives you a bitter pill like the doctor. This is for your own good. Both happiness and sorrow are God's gifts. Nobody can comprehend His Divine Leelas. Whatever activity you undertake, unity should be the undercurrent. All people should live in peace and harmony wherever they are. Even if you come across an opponent, greet him with love. He will automatically respond with love, since the whole world is filled with reaction, reflection and resound. Suppose there is unrest in you mind. It is not because of external factors. Your own deficiencies and faults are being reflected in the form of unrest.