The psychic abilities are a part of who we are as human beings...anyone is capable of development and enhancing of this talent, skill, gift. To make it a spiritual exercise is a personal choice. Many do and many do not enhance their gift with spirituality (this is not about religion...it is the innate urge within the human being to strive for spirituality).
To be a psychic is to use the 5 senses (sight, hearing, smell, touch, taste) and to add intuition and I know (this comes from the heart....it neither sees nor hears...it just knows) through our natural sensitivities to form a deeper understanding of the 'more' in life. This can and often is, done without any spirituality whatsoever.
The spiritual path leads us to our awareness of God (according to our own understanding) in all that life offers...the gifts of our talents and skills, including the psychic can be a part of this understanding. They can also express without this spirituality. We choose how we apply our talents in life.
The psychic reads the vibrations around the individual and thereby draws their demonstration...mostly telling the client what they want to hear, rather than what they need to hear to progress. The medium attunes to spirit realms and receives what the client needs to enhance their spirit in life.
The natural law works whether we recognize it or not. The law of attraction is based on our own ability to learn and grow. We become spiritual in our application, and the psychic abilities become spiritual. We make this choice in our own growth. An athiest is still capable of demonstrating psychic or mediumship abilities.
When we are sincere in our efforts to work in spirituality, we find those from spirit (guides, teachers, helpers, etc.) who wish to work on that vein as well. The law works whether we like it or not...it shows us that those that can and do work with us are either the philosophical kind, or whatever lessons that life presents. We can only raise our own vibration to where we have fitted ourselves to be...and those in that level can commune with our energies.
As to it being of the devil...is that what they truly think of their own loved ones, relatives and friends who are in spirit realms?