Sanatan is not a religion, it's refers to the “eternal” truth and teachings of Hinduism. It can also be translated as “the natural and eternal way to live". The term is used in Indian languages alongside the more common Hindu Dharma for Hinduism..

The eternal Truth is a divine Person, and His Name is Jesus. Why should you follow Him? He said, “You are from below; I am from above. You are of this world; I am not of this world. I told you that you would die in your sins; if you do not believe that I am He [God], you will indeed die in your sins.” ~ John 8:23-24

The Abrahamic religions - Judaism, Christianity and Islam - share some rituals with Hinduism, such as fasting and pilgrimage. In Hinduism the pilgrimage is the Parikrama temple.
There are similarities in the concept of God. All believe in the existence of a universal supreme power, in Hinduism it is Brahman and in other religions it is God.
Brahman is the only binding union, behind the diversity of all that exists in the universe. In the Abrahamic religions it is God. It is believed that the worlds created by God will perish, which is similar to the Hindu concept of the infinite process of generation and annihilation.
There are no prophets in Hinduism, nor a holy book. The spiritual knowledge of Hinduism is contained sacred texts called (what is heard) and (what is remembered).
After death one enters Paradise or Hell depending on his actions. Hindus believe in the cycle of reincarnation.
All of them fight (Satan/Asura), who is in constant war against man and God.

The Sanatana Dharma is known as the eternal religion because it represents the eternal idea of perfection. In this hallowed tradition, there are as many paths to God as there are individuals. Not everybody understands this profound truth.

It never enforce to believe..

I believe in Satan

Jesus teaches and convinces, and never forces anyone to be convinced of the principles of the Gospel.
The evidence for that is in the Bible:
Then the disciples came to him and asked, “Do you know that the Pharisees were offended when they heard this?” He replied, “Leave them; they are blind guides. If the blind lead the blind, both will fall into a pit.”
The Quran says:
‘’There is no compulsion in religion. Righteousness is now distinct from error. He who disbelieves in the idol and believes in Allah [God] has grasped the firmest tie that will never break. Allah is Hearing, Knowing.
Allah is the Guardian of those who believe. He brings them out from darkness into the light. As for those who disbelieve, their guides are idols, they bring them out from the light into darkness. They are the companions of the Fire and shall live in it for ever.’’

Sanätana-dharma does not refer to any sectarian process of religion. It is the eternal function of the eternal living entities in relationship with the eternal Supreme Lord. Sanätana-dharma refers, as stated previously, to the eternal occupation of the living entity. Sri Rämänujäcärya, a legendry Acharya in the line Bhakti-yoga has explained the word sanätana as “that which has neither beginning nor end,” so when we speak of sanätana-dharma, we must take it for granted on the authority of Sri Rämänujäcärya that it has neither beginning nor end. In other words, Sanatan means eternal and cannot be restricted within the boundaries of time, space, nation, caste, color, or creed.

The word Dharma refers to the intrinsic characteristic of the living being. That means the Dharma of the living being cannot be changed. When we use the word ‘living being or living entity’ we refer to all the spirit souls who are embodied in various species of life. ‘Dharma’ is characteristic of the soul which is independent of the type of body in which the soul is residing.