At the end of the 1980's, while the first HIV/AIDS cases appeared, together with the Ethiopian Government the Ethiopian Orthodox Täwahedo Church (EOTC) committed officially itself to the fight against HIV/AIDS. In the 1990s, followers of the Ethiopian Church on their side started to dedicate themselves to holy water ritual hoping to be cured miraculously of HIV/AIDS. In 2004, the EOTC started to receive American subventions in order to promote abstinence and faithfulness among its followers. Two years later, antiretroviral treatments began to be largely and freely distributed entering in conflict with the spiritual values of the holy water cure, which excludes any other kind of therapy. This study, combining health and religion socio-anthropology approaches focuses on the way the Ethiopian Christianity in its two components - both institutional (EOTC) and ritual (Ethiopian Church) - involved itself in the fight against the epidemic. Furthermore, it addresses the way americans' grants and antiretroviral treatments became factors of change in this particular ancient Church. The analysis shows that traditionally, the Ethiopian Christianity is not a body in charge of regulating its followers' sexual behaviour. It is significant that followers infected by HIV seek healing through holy water cure for it reveals that in this religion, the emphasis is being put on forgiveness and redemption. Within the sociology of religious facts, this approach brings to light the fact that the Ethiopian Christianity is a religion of forgiveness, and thus that it will focus more on healing than prevention. In this respect, one of the strength of the thesis is to have examined healing as an object of research in itself. Therefore, healing appears to be the inverse glint of the entrance in the sickness. It can be then conceive as a process-event in which many actors and institutions participate.