Ok Prasad, why do Hindus light a lamp when they pray?
Well, to us light symbolizes knowledge, and darkness, ignorance. The Lord is the the enlivener and the illuminator of all knowledge.
Hence light is worshiped as the Lord himself.
When lit by spiritual knowledge, our negative tendencies are slowly exhausted and the ego too finally perishes.
Hindus see the Lord as the entire creation. He is therefore the true owner of the house we live in too.
Spiritual thoughts and vibrations are accumulated through regular meditation, worship and chanting that is done in the prayer rooms or at the altars and this pervades the air... so when we are tired or agitated, by just sitting in the prayer room for a while, we feel calm, rejuvenated and spiritually uplifted.
The tilak( usually sandalwood paste) invokes a feeling of sanctity in the wearer and others.
Man is regarded as the most beautiful, living breathing temple of the Lord! Therefore touching another with the feet is akin to disrespecting the divinity within him or her. This calls for an immediate apology, which is offered with reverence and humility.
Most devout Indians fast regularly or on special occasions like festivals.
The ringing of the bell produces what is regarded as an auspicious sound. It produces the sound Om, the universal name of the Lord.
The lotus is the symbol of truth, auspiciousness and beauty.
He who does actions, offering them to the Supreme, abandoning attachment, is not tainted by sin, just as a lotus leaf remains unaffected by the water on it.
Each one is associated with lotus that have a certain number of petals.
When the conch is blown, the primordial sound of Om emanates. Om is an auspicious sound that was chanted by the Lord before creating the world. It represents the world and the Truth behind it.
Shaanti, meaning "peace", is a natural state of being. Disturbances are created either by us or others.
Therefore, peace underlies all our agitations.