If you are interested in how to achieve eternal life in the true sense, then the truth shall set you free.
Your current composition is body, soul and spirit. Soul and Spirit are commonly used interchangably as synonyms but they are not. The Soul in you is the same Soul in all of us. It is ubiquitous and pure. The Spirit however is unique to you. The Body is also unique to you and is the vessel that allows the Soul and Spirit to be in close proximity to each other.
In order to achieve eternal life you have to achieve something very important before you die. You must bring the Soul and Spirit together in such a way that they will not separate after death.
To give you a mental image that will be helpful I need you to see in your mind's eye blackness except for an extremly thin but effulgent light, like a door barely cracked open. This light is your soul and is infinitely long like a bright line that pierces an infinite blackness.
You are circling this pole of light like a spiral staircase. This luminouse, cloudlike spiral is your spirit. The blackness is the body that has forced these normally far apart lights, together.
The infinite lower part of the lightline that no longer has the spiral of a spirit progressing along its length is the recording of everything the Spirit Experienced when in a body. So as you look down the long lightline, some parts are pure white and untouched and some parts are colored like a rainbow or splatters of paint mixed together. Where the Spirit was close enought to leave an impression upon the pure awareness of Soul, there is a hue of color and images, like a recording on a DVD or CD. Where the light is unmodified is where, during its uncarnate state, was too far away to modify soul.
This duality of Spirit and Soul is the dance of life. Apart, the Spirit has no memory and the Soul has no experience. Together they navigate experience, apart they are incomplete. Just as an atom must have a proton and a electron, so must life have spirit and soul.
The Spirit is always moving and vibrating to the Karmic residue left over from countless lives of action. This memory of the current Karmic State is in progress, modifying and morphing from second to second as one performs action and inaction. During death it is a static vibrational pattern awaiting a body to allow it close enough to life giving soul.
In your body this spiral of Spirit Energy forms 7 major whirls that are called chakras. Each swirl of energy is a quantum level of life force that is unique to you.
So not only does one have to combine the Spirit to the Soul, it must be done sevenfold. All 7 chakras are whirling at different speeds and different levels of energy depending on how balanced one is.
The 7 chakras each represent a wisdom. The lowest chakra at the base of the Spine is awareness and it is associated mostly with desire, as there can be no desire without awareness. This is also the chakra that rules your sex life. Some individuals have only an energetic lower chakra and thus are ruled by their desires.
The highest chakra is at the top of the head and is holiness. When that chakra is fully energized you are one with the Soul and it explodes into a flower with a thousand petals.
The chakra just above the base of the spine is infinity. When even partially energized it gives the individual gut knowledge of the future. The chakra below the sternum is eternity. This is activated by controlling the breath to the point that the in and out breath are in perfect balance in the now.
The middle chakra is the wisdom of Balance. It is the hardest to activate for it is only activated when the other 6 chakras are in rotational unison.
The heart chakra is Oneness for Oneness occurs in the heart. The brain chakra is faith. For faith is impossible without belief and trust, which resides in mind seated in brain.
In order to bring the Spirit Spiral which manifests as 7 whirling energy chakras into unison there are special exercises, which can bring this into reality.
There are special mantras which can energize each chakra. There are meditative diciplines which help remove the karmic disturbances in the Spirit so it can bind to the Soul.
There are a series of Yogi's who have mastered these techniqes and have passed the information from generation to generation via disciples. The one who introduced these secrets to immortality is the same one who incarnated 2,000 years ago and taught it to one of his diciples. That disciple was Thomas the Twin.