Why is it good to invest MF for the long term when they don't guarantee me the returns?

I want to make an investment in shares for a long term tenure of about 10 years of amount 4 lacs . Please guide me with some good names and the results reflected by those shares. Also any expert advise are welcomed even if not to context of Question?

I am looking to invest in Nifty or Sensex as part of long term investment. Do you recommend an index fund or an index ETF?

I want short term profits and heard of fidelity mutual funds. Kindly share some good funds to invest in.

How is UTI Nifty Index fund beneficial in case of long term investment?

Due to bad news some good fundamental stocks falls very huge after that, can we add it in our portfolio, for long term investment?

Why is promoter holding of Larson and tubro so low considering the strong fundamentals of the company. Is it a good company for long term investing?

Are investment returns guaranteed in a unit-linked investment product?

What are some good mutual fund portfolios for investing Rs. 10K per month? My asset allocation is 30% debt, 70% equity and my goal is retirement saving with an investment horizon of 25 years. I have moderate risk appetite

I want start my own export business but don't have enough finance ,is there any angel investors who can help me??

Will the actual result of the tax on LTCG make a significant difference to equity mutual fund returns over a longer period of time? Is it something we can ignore?