Confinement of spin-1/2 quarks by an infrared-singular effective gluon propagator is shown to work in three space dimensions. The exact infrared behavior of the quark propagator is isolated. In the infrared limit the propagator vanishes as the pole moves to infinite energy. The same singular interaction is used as the kernel of the Bethe-Salpeter equation for bound states. The divergence from the kernel exactly cancels the zeros of the propagator to produce an infrared-finite bound-state equation. The cancellation occurs only when the kernel has the form of a generalized instantaneous Coulomb interaction. The existence of confined solutions is demonstrated.