Q: Why we should not believe in superstitions?
A: A real Sikh never believes in superstitions.
Sikhism instructs not to believe in good moments, or bad moments, good days or bad days, good numbers or bad numbers. According to Sikhism, all days of the week and all numbers are the same, no one day or a number is better than the other.
Many Hindus believe Tuesday to be a sacred day. Hindus that eat meat do not eat meat on Tuesdays. Muslims consider the month of Ramadan sacred. Some Christians consider 666 as a bad number or the number of the devil while 777 as a good number. Sikhism does not endorse any such beliefs.
One of the superstition include that if a cat crosses your way, most people would turn back home and go and wait there until some time passes because they believe something bad might happen to them. If someone is leaving the house and you sneeze, it is believed that you will not be able to accomplish your work. Whether it is a black cat, a brown cat, whether it goes in front of you or behind you, it doesn't make any difference to the real Sikh. Whether some one sneezes or coughs, it doesn’t make any difference to the real Sikh. Sikhism considers these types of beliefs as superstitions.
Furthermore, Sikhism instructs not to fast, perform animal sacrifice, go on pilgrimages, conduct self torture, or any other similar tasks. The only way to please God and be one with Him is to love Him. One need not perform any rituals or believe in superstitions to receive God’s love.