Create a digital art illustration encapsulating the essence of Luke 18:16-17. Depict a serene exterior scene where an altruistic figure beckons a diverse group of children of various descents including Caucasian, Hispanic, Black, Middle-Eastern, and South Asian. These children joyfully come unto the figure, displaying their innocence and faith. This moment is uplifted with a celestial vision of the kingdom of God, embodied as a radiant city floating in the sky. The figure's message and the kingdom of heaven should intertwine symbolically throughout the scenario.