The common and easiest answer is to ramp up the ambient in the surface settings.You may have to adjust the color as well because it tends to “fade”. The second less easy answer is to use the uberarea light shader in light presets/omnifreaker. Those actually cast light but you may have to play with the surface settings some to get it to look the way you want.
If you just want it to glow but not emit light onto other content, then increase your ambient until the glow matches your tastes.
If, on the other hand, you wish for the glow to light other objects in the scene, you can apply the UberAreaLight on the surface you wish to emit light (Control-Click to maintain your current textures). Then adjust the intensity in the “Surfaces” tab.