It is not permissible to have one place of worship that gathers the three religions. This is because this place will not be established on piety, but will be established on Shirk (associating others with Allah in His Divinity or worship) and worshipping people other than Allah. There is no sound religion except Islam. Allah (Exalted be He) says:
And whoever seeks a religion other than Islâm, it will never be accepted of him, and in the Hereafter he will be one of the losers.
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.