Question 1: How to recognise a sincere and truthful devotee of God?
Question 2: Who is deemed an unspiritual and worldly-minded person?
Answer 2: "A worldly-minded person is a prey to sexual thoughts, and thoughts of hatred, anger and revenge. He is enslaved by these two type of thoughts which take possessions of his mind. He does not know the laws of thoughts, and how to divert his mind, and fix it on good, noble thoughts. He cannot resist an evil desire, craving or temptation on account of his weak will. He is completely ignorant of the nature and workings of the mind. His position is extremely deplorable, despite his earthly possessions and knowledge obtained from universities. Dispassion and discrimination have not awakened in him. He has no faith in saints, in scriptures and in God...." (pg. 355, Science of Yoga, Vol. 2 by Swami Sivananda)