The symbol of the rosy cross played a substantial role within the system of Thelema as developed by Aleister Crowley. In a cosmological context, the rose is Nuit, the infinitely expanded goddess of the night sky, and the cross is Hadit, the ultimately contracted atomic point. For Crowley, it was the job of the adept to identify with the appropriate symbol so to experience the mystical conjunction of opposites, which leads to attainment. In this sense, the rose cross is a grand symbol of the Great Work:

https://en.wikipedia.org/wiki/Rose_Cross