Several routing protocols have been designed in the recent years to support different wireless sensor networks requirements. In this paper, we introduce a new on demand routing protocol, Reliable Fault-Tolerant Multipath (RFTM), to improve the reliability of data routing in wireless sensor networks. RFTM is a multi objective routing protocol that meets diverse application requirements by considering the changing conditions of the network. The protocol takes into account both reliability demand and link quality to determine the number of desired multiple disjoint paths between the sink and source nodes. With the advantage of data splitting method based on erasure coding the packets are encoded at source nodes and the sink node obtains the data by decoding. Moreover, the sink node can make intelligent decisions based on the node's available resources, hop count to the source and delay to lengthen the network lifetime, provides fault-tolerance and achieves the desired reliability that meets the network state and the different application requirements.