If you believe that what Jesus said is true for you, then yes you are an 'alien' in this world.
Speaking to mortal consciousness, Christ Jesus said: "You are of this world; I am not of this world." Christ Jesus "had come from God and was returning to God" (John 13:3). And before the crucifixion, when praying for his disciples (and all who followed his teachings), he said: "They are not of the world, even as I am not of it" (John 17:16).
The consciousness of Truth and Love brought to light in Jesus' realizations and teachings are not of mortal, limited or worldly consciousness. Divine consciousness has no relationship with biological or material theories, besides being their opposite.
You, as an emanation of divine Mind, are alien to thinking and living that includes limitation, fear, pain and disease. These by-products of worldly consciousness are foreign to your natural awareness. Where you come from and where you are going includes no fault, pain, accident, pressure or decay. You were born and you are destined to be present in the consciousness of complete, ever-rejuvenating Love.
You are at home, in heaven, in the consciousness of your at-one-ment with Life's wisdom, intelligence and grace. This is your homeland. You are a foreigner, an alien, anywhere else.
Bring heaven (divine consciousness) to earth (our present experience) today by seeing our home right here -- spiritual ideas and concepts as present facts.