Omprakash Ji
The relationship of Niyama is with personal religion. The Niyama are described in 32nd Shaloka in Patanjali Yogadarshana, which are as under:
SHOCH SANTOSHTAPA SAWADHAYASHAWAR PRANIDHANANI NIYAMA (Yog 2/32)
  1. Shoch (Sacredness)
  2. Santosh (Contentment)
  3. Tapa
  4. Sawadhaya (Introspection)
  5. Ishwar Pranidhan (Shelter to God)
SHOCH-SHOCHTAWASWANG JUSUSHUAPASA PRESHSANSAGARG (Yog 2/40)
ADIBHARGATRANI SHUDHYANTI MANA SATYAN SHUDHYATI,VIDHYA TAPOBHAYAM BHUTATMA BUDHIGAYARNEN SHUDHYATI (Manu Smriti)
  1. Shoch : The meaning of Soch is sacredness, purity. Shoch is of two kinds, internal & External.
    External shoch: To clean body with earth, soap, water etc., to clean clothings , places and utensils etc.To clean with Yogic activities like Basti, Dhouti, Neti etc is external Shoch.
    Internal Shoch: To clean mind, brain & Inderia (Senses) is internal Shoch. The sex, anger, ego, greed, love, jealousy, sorrow, sleep etc are oxidants of mind. It gets purified only after removal of these. Mind is purified by vegetarian food, want less actions, company of good people, introspection, pranayam and knowledge. Shoch is to remove bad thoughts with good thoughts. Also with Tapa, mind gets purified. With internal shoch results in cheerfulness of mind, freshness in brain and sensing (indriya) get controlled and thereby you are able to know self.
  2. SANTOSH: SANTOSHAD ANUTAM SUKH LABHA ( Yog 2/42) Santosh :It is said in upanishads that “ Na Viten Tarpniyo Manushya”. It means that human beings will never get satisfied through wealth, it will only through Contentment. Contentment is to remain satisfied with whatsoever you have and not to greed for more. Contentment is considered best of all types of wealth. Only through this, human beings get supreme satisfaction. One should be contented in three acts;
    1.To donate
    2.To do Tapa(devotion) 
    3.To learn
    The discontented person keeps worrying for what he is not having or not getting enough.He suffers from all kinds of sorrows. His mind does not remain peaceful and happy.Therefore, whenever good thoughts take birth in mind and contentment gets rooted, one gets inclined towards Yoga.
  3. TAPA: KARYAINDRIYA SIDHIRSHUDHI DAYATPASA ( Yog 2/43) : Tapa is to tolerate oppositions & controversies and move ahead in Yog Sadhana. To control body, mind, brain & senses (indriya) with right practice is called Tapa. Through Tapa, one gets engrossed in Yoga irrespective of summer-winter, hunger-thrust, happiness & sorrows, respect-insult etc. If the follower of Yoga cannot follow this type of Tapa, He cannot get desired results out of Yoga. In case one does not do Tapa, he can not destroy bad impulses and remain affected by sufferings of body, instability of mind and sorrows & sadness. The Yoga sadhana shall be fruitless under such circumstances. Hence, Tapa purifies body and mind.
  4. SAWADHAYAYA: SAWADHAYAY DRIDHTI DEVTAM PROYOGA (Yog: 2/44): One does not get true knowledge without Sawadhyay (Introspection) . One should regularly read Vaidas, Upanishads, Shreemad Bhagwat Gita, Literature on Spiritualism and books on Yoga. Continuous chanting of Omkar & Gayatri Mantra is Sawadhayay. By reading of these legends and continuous chanting of Mantras, one gets supreme knowledge effortlessly and it also increases will power. The follower gets rid of sadness & sorrows, sufferings & troubles. It stimulates vigour and follower gets name and fame.
  5. ISHWAR PRANIDHAN: SAMADHI SIDHIRISHAWAR PRANIDHANAT (Yog: 2/45): It means to surrender all deeds including their results to God. ISHWAR PRANIDHAN is supreme out of all principles. The Sachidanand, Param braham God is complete in all respect. Completeness gives birth to completeness. Even one removes completeness out of completeness , still there remains completeness. Hence, in case follower surrenders all his deeds to God, he can remain engrossed in Yoga.The first two stages of Yoga YAMA & NIYAMA are very essential for the follower. Therefore, in case one does Asanas etc without following these stages, one does not get true benefits of Yoga.The person doing Yog Sadhana after following Yama –Niyama is the best person.