Every single step done by us is written by God. Then why, by doing good or bad deeds, do we go to heaven or hell, while we never perform any step without God’s permission?

Even that is written by God.

One can attribute the law of Karma for the grown up adults inflicted by deadly diseases like cancer, But how one can explain innocent children getting this deadly disease?

Everything in this world happens according to the Karma. Children get afflicted with deadly diseases like cancer because of their Karmas in their previous births.

Why does God create this world? Why does he make us suffer? Why can’t he forget all our sins and give us all Moksha instantly and wind up His Show? Is it His Lila to make us suffer?

When one participates in a motor race or wants to become a solider, he very well understands the risk involved in the job. Doesn’t he?
So, even after you witness so much of suffering in the world, you wish to continue the same lifestyle. That just implies that you are ready for the battle!
Joy or sorrow does not arise from any object or event as you imagine. It is in your mind. So, the key is to keep your mind aloof and unaffected from the happenings of the world. Yes. That is the solution. God is so compassionate that He has also shown the techniques, ways and means to achieve this state of aloofness. That shows His grace. What more? He shows no discrimination in showering His grace, based on caste, creed, religion, gender, wealth or power.

Why does Bhagavan Krishna give sufferings to even those who love him?

The hell is full of sorrows and the heaven is full of joy. But for anyone and everyone on earth, it is a mixture of both joy and sorrow.
To forget this mixed results of joy and sorrows, we should be totally immersed in Bhagavan Krishna’s eternal bliss.
It is only in order to get his most loved ones into that state, Krishna, an ocean of compassion, gives sufferings.

In age of Kali too there are people who are very much devoted to their guru and god, feeding the poor and the cattle, living lives in an orthodox manner. But I find these people suffer the most and the worst conditions in life. It can be due to their karma but when a normal man sees these good people suffer the most, he starts to believe that there is no use for dharma, god or guru for life. Why should God make such good people suffer without considering that these suffering would mislead the normal people seeing these devoted people suffer?

Let us assume that a person is packing up his luggage to go on a long travel and is scheduled to leave that day. After taking his regular meals, he realizes that there is a little more food left. He would then decide to eat up the remaining food also, because he would not be home the next day to consume the same.
In just the same way, those people for whom the current birth is the last would have to undergo their remaining Karma some way or the other. Hence good people wipe out their Karmas through such sufferings.

We know that after death we take new birth according to our karmas. I would like to you know which act of karma determines the gender – male or female?

The attitude is what determines the gender.

If a man knows that he being under a suffering or joy for this specific Karma he has done in the past, he would take that as a lesson and would start leading a life free from evils. Why are we (normal people) not provided with that power?

Civil, criminal and social laws dictate that certain actions are right and certain actions are wrong. For every wrong act, a punishment is ruled, and the nature and severity of the punishment differs based on the nature of the crime. Hence it is enough if the Government spreads awareness among the public about the laws. Imagine what would happen if the Government decided that all the citizens be taken to the prisons to see the punishments that are being undergone there.
The already confused man would panic and lose his morale. One’s self confidence will touch such an abyss that he will be scared to do anything at all, based on his visual experience!
So, cognizance of something is entirely different from experiencing or visually witnessing it.
God gave us the Shastras through the Mahatmas that help us decide what is right and what is wrong, just like the laws of the land in our example. It is for us to believe in them and follow them.
In the world, every moment, we witness that there is suffering on one hand and joy on the other. What more lesson do we need on the Karma Theory?

As per Hinduism, we take birth in this world due to our Karma (Deeds or misdeeds in our previous generation) So many deaths occur due to natural calamities where thousands of human lives are taken away. Man made calamities on account of bomb blasts also take away precious human lives. What is the sin or the Karma these human beings have committed whose lives have been plucked by the Almighty in few seconds of such calamities?

It is true that we take birth according to the karmas of the past births. Regarding the lives lost, it is not possible to find out the karma of each and every person and account for the same. But one thing can be said for certain. God is perfect. An imperfection cannot come from the perfect.

If everything happens according to the Will of the Lord, then why does the individual get affected by his actions whether good or bad?

You are right. Everything is controlled by the Lord and no atom can move against His divine will. When that is the case, when something good is accomplished by you, why do you take credit for it? That is because of the sense of ‘I’ or ego which comes into play. As long as that feeling exists, it is impossible to believe, in the true sense, that you are not responsible for anything – good or bad.

Sometimes, when we see people suffering from problems, we attribute it to being the effects of the sins of the previous birth. What would have happened in the very first birth, when there wouldn’t have been any ‘previous’ birth and hence no merits or sins associated?

Yes. In the very first birth, everybody was given all the amenities alike and good health and happiness alike too. Then, it is because of each individual’s greed that they started committing sins.