How do we know that we are in the right path or not in life?

If we have faith in the Almighty and worship Him in any path prescribed by the great devotees and the Vedas, then we are in the right path. If not, then we are not!

1. How can I get mental peace? 2. How can I attain God? 3. What is the way to success? 4. Is it possible to earn a lot of money? Please let me know.

You have wished for ‘Dharma’, ‘Artha’ (wealth), ‘Kama’ (ambitions) and ‘Moksha’ (God). Srimad Bhagavatam says that all these four can be attained by performing service to Lord Sri Hari.
Chanting the Mahamantra and pleasing the Lord is the easiest way to serve Sri Hari. So start chanting right away and attain these four very easily.

If life is a series of experiences based on our karma, where is the doership for anybody?

That is true. It is ideal not to have the sense of doership at all. However we forget this very fact due to the veil of Maya and we tend to attach the sense of ownership to each and every act and each and every thing in our life, every moment of our life. That is the reason for all the sufferings. The true realization and experience of this fact will dawn only by the grace of God, which can be invoked easily through chanting the Mahamantra.

How is my life?

If you are good today, the future also will be good to you.

I have been listening to Bhagavatam over the last few years. However, in the worldly life: I come out with lot of contradictions if I want to practice even a small portion of it – integrity of friendship, ego, other emotions, to name a few. How do I overcome these and be at peace?

It is very nice to note that you have been listening to Srimad Bhagavatam for the past few years.
Srimad Bhagavatam is verily described as the essence of the Vedas which is nothing but eternal Knowledge. It has answers for all your questions. You don’t need to look for any other external sources for answers nor ask anyone. Be strong in your quest, and keep going through the great Purana over and over again until you find the answer. You will definitely get answers to your queries.

Why do people find it difficult to realize the true essence and purpose of existence?

If an oil lamp is lighted, the flame always goes upward. Similarly, water always flows downward. A small child has a fascination for sports, music and fun. This is a natural phenomenon, which, in other words, can be put as the will of Lord Sri Krishna.
Thus, the vision of all creatures, right from a small worm to a mammoth elephant, is outbound. Since we have taken innumerable number of births earlier, and in all those births, our vision was outbound, it is very difficult for us to turn our vision inward in this birth.
The true purpose of existence can be understood only if one attains a Guru, who, not only knows the true purpose of existence, but has also experienced it.

What do I do if I get disrepute for doing something that others don’t like, even though I am convinced that it is right?

When you truly feel that something is right, you should go ahead with it and not worry about the repute or disrepute that would follow.
In general, the ways of the world and the conscience do not go along very well. One should decide which one should be given preference. If conscience is to be given preference, then one should not care about the society and worry about anything else. If one considers society to be more important, then he has to go along with it.

What is the easiest way to fructify this birth?

The easiest way to fructify this birth is to chant the Mahamantra.

What is life and who is God?

When anyone touches you, you feel it, don’t you? That consciousness is God.
When you consume food, you feel its taste, don’t you? That consciousness is God.
When there is a sound, you hear it, don’t you? That consciousness is God.
When there is a fragrant flower, you sense the smell, don’t you? That consciousness is God.
When there is a beautiful sight, you perceive the vision, don’t you? That consciousness is God.
God is nothing but the all-pervading consciousness.
Becoming one with the consciousness by removing the blocks that prevent it – that truly is Life.

What should be the aim of life? To merge with the Oneness or to render constant devotional service to the Lord?

To realize the Lord Krishna within you – that is the aim of life.