This paper presents a molecular theory of the thermodynamic properties of reversible gels whose junctions are formed by the clustering of an arbitrary number of associating groups, or segments, on the constituent molecules (or primary chains for polymeric gels). Cross-linking by the microcrystalline segments on the polymer chains or by associating groups attached to the chain ends are examples. We focus our interest specifically on the interference between gelation and two-phase separation. We study how these transitions depend on the molecular weight, functionality, and the aggregation number (multiplicity) of the network junctions.