Consider:
الْعِلْمُ نُورٌ وَالْجَهْلُ ظَلَامٌ — Knowledge is light and ignorance is darkness.
The contrast between light and darkness reinforces the difference between knowledge and ignorance, illustrating the effect of antithesis (tibaq). The language is also figurative: it does not literally identify knowledge with physical light.
One statement can combine figurative expression and embellishment. Mere oppositeness, however, does not automatically create a successful rhetorical device.