A respectful and devotional Christian art inspired by the essence of Romans 11:18. Instead of focusing on the style of a specific contemporary artist, let's incorporate three defining adjectives - harmonious, complex, and vibrant - reminiscent of the Post-Impressionist era or early 20th-century artworks, primarily executed in oil paint. The canvas should be void of text or any inscribed words, instead, the emotions and messages should be conveyed purely through visual elements.