Visualize a scene from the biblical passage Exodus 13:21. During the day, an ethereal pillar of cloud, symbolizing divine guidance, leads a crowd of individuals across a terrain. By night, the celestial guide transmutes into a breathtaking pillar of flame, providing both guidance and illumination. Render this scene adopting the nuanced detail, emotion, attention to light and shadow, and realism often seen in Renaissance era artwork, predominantly executed in oil paint.