Birth then is dependent on karma, but Bhagwan's kindness is not dependent on karma, that is dependent on bhava (emotion, feeling).
Anybody who desires, be he brahmana, be he kshatriya, be he vaishya, be he shudra - [whoever] has a feeling for Bhagwan can gain Bhagwan. They can glorify Bhagwan, so really Bhagwan's glorifying cannot only be done by brahmanas. Four castes of people can do bhakta (service) then. But an acharya (preceptor) cannot be people of the four castes. For this purpose then is the drum (proclamation) of Adi Shankaracharya:-- यावतà¥à¤ªà¤µà¤¨à¥ निवसति दà¥à¤¹à¥ तावतà¥à¤ªà¥à¤à¥à¤à¤¤à¤¿ à¤à¥à¤¶à¤²à¤ à¤à¥à¤¹à¥ ठ" yaavatpavano nivasati dehe taavatpR^ichchhati kushalaM gehe I" [bhaja govindam v6] `When one is alive, his family members enquire kindly about his welfare. Later, when the body is old and decrepit, nobody in the house asks for word of him' Therefore; à¤à¤ à¤à¥à¤µà¤¿à¤¨à¥à¤¦à¤ à¤à¤ à¤à¥à¤µà¤¿à¤¨à¥à¤¦à¤à¥¤ à¤à¤ à¤à¥à¤µà¤¿à¤¨à¥à¤¦à¤ मà¥à¥à¤®à¤¤à¥ ठ" bhaja govindaM , bhaja govindaM . bhaja govindaM muu.Dhamate I" [bhaja govindam v1] `Worship Govinda, worship Govinda, worship Govinda O, foolish mind!' Actually, before senility, anybody of any caste should be mindful to do sufficient bhajan and puja of Bhagwan, for in this is happiness. Happiness will not be being born in any caste. Happiness will then be from bhajan of Bhagwan and to do bhajan to Bhagwan is just man's right. There is no talk that one must be a brahmana in order to get mukta (liberation). If bhakti (service) of Bhagwan is done then [all] is well, [but if] not then brahmanas also come to the ruler of hell, and the devout shudra can gain Bhagwan. Wherever happiness is to be, there nobody is brahmana, is not kshatriya, is not vaishya, is not shudra. In Paramatma there is no difference in anyone, the difference then is in everyday affairs. [Shri Shankaracharya UpadeshAmrita kaNa 97 of 108] ... Another way of misapplication of the body and mind is that people stay attached in supporting caste and the height of the lineage. You have gotten the body of a human being; any caste you have become born in - brahmana, kshatriya, vaishya, shudra - whatever caste you have become born in then all have the right to remember Bhagwan and all have the right to reach near to Bhagwan. In between, difference of "class" stays, this difference, any such matter is not a thing for much consideration. Wherever you have been born, then you have been. Now then you should make such effort that you are not born again; not so that whatever caste you are born in, your life is lost in support of it. This then is a dharmashala (halting house for pilgrims). Having come here you should perform the principal work, not work in justifying the dharmashala. In the life of a human being that mind is a thing to be applied in Bhagwan, from that [understand] it is improper to do improper conduct and/or sinful living. [Shri Shankaracharya UpadeshAmrita kaNa 105 of 108] translation - Paul Mason © 2007, 2009 http://www.paulmason.info/gurudev/upadesh.htm