As human beings, our knowledge is either derived from our experience, which includes the experience of our past generations as recorded and passed on to us, or the exercise of our mental and physical power, or from what Allah has chosen to tell us. It is important to realize that our knowledge is neither perfect nor complete. Since much of it is the result of experience, it is subject to numerous factors which could limit, modify or distort it. The domain within which we can exercise our power is vast indeed, and the result is that our knowledge can be right and extensive. Nevertheless, it cannot attain perfection. Perfection belongs only to Allah.

In the Qur'an, references abound to what is termed as "ghaib". This is an Arabic term which refers to what is withheld from human beings. It covers a vast area of existence, as well as the working of numerous forces in the universe. It also includes the world which we feel to be definitely in existence, although we cannot perceive it. As believers, we realize that Allah has chosen not to let us into the secrets of this 'ghaib' because the knowledge of such secrets will not help us in the fulfillment of the role Allah has assigned to us when He created us and gave us the earth as our field of operation.

Hence, when we find ourselves facing something that we cannot fathom, we do not try to provide for it an explanation for which we have no solid basis. We accept that it belongs to what has been withheld from us. We recognize that it is fully known to Allah and that He has kept its knowledge [away] from us because it is not necessary for us in the carrying out of our task.

Some of the points you raise belong to that realm. As such, I am not one to venture any hypothetical explanation for them. I simply tell you what Allah has chosen to tell us about them. Besides that, I have nothing to say.

What we can say about the beginning of life is that life is part of Allah's creation. The whole universe is also created by Allah. It is, then, conceivable that there was a time when the universe did not exist, because Allah had not created it yet. Allah Himself has existed all along, even before the beginning of time. All His essential attributes, including creation, have also been in existence with Him. As He existed, He has been the Creator. He might have created a different universe before the one that exists now. All that is something that we cannot know for certain. All that we need to know is that when Allah wishes to create something, He only need to give His command for it to be, and it exists. This applies to any small matter, in the same degree as it applies to the universe as a whole. I simply do not know how the universe was formed. Scientists may have their theories, some of which may be nearer to the truth than others. From the Islamic point of view, we simply say that the universe was formed by Allah's will and according to His commands.

Similarly, life began when Allah willed that it should begin. You ask about the original substance of life. If your question relates to human beings, we take what the Qur'an says about this. The first human being to come into existence was Prophet Adam, peace be upon him. Allah tells us in the Qur'an that He made Adam of clay and then He breathed into him of His own spirit. Human life is, then, made of the combination of the clay and the spirit. Scientists say that human existence on earth is a recent development. It may be so. There might have been some other creatures of men living on earth, and these could have been of a primitive variety of men.

That does not contradict what I have just mentioned about the combination of clay and spirit in the making of man. We simply cannot specify a date for the beginning of human existence. Nor can we say anything about the timing when the clay was combined with the spirit by Allah's order.

Allah tells us in the Qur'an that we will be raised for a second life after we have died. Therefore, we have no doubt that there will be another life after this one. It only stands to reason that human beings, who have been given the ability to choose what they do and provided with guidance to show them the right path, should be held to account for what they do in this life. That will entail punishment or reward. This will take place in our second life.

You ask about the end of the world. There are references in the Qur'an to the heavens being rent asunder, or breaking up. That may be a reference to the end of the world. There is also a surah in the Qur'an which speaks of a particular quake which will shake up the whole earth and to bring out into the open all that it is burdened with. But the life will certainly come to an end when a particular event shall take place. The Qur'an tells us that this takes place at the blowing of a particular trumpet. Knowledge of that trumpet and how and when it is blown is part of what Allah has chosen to withhold from us. What we know, because Allah tells us of it, is that when the trumpet is sounded, all living creatures on and in the earth will be stunned and become lifeless. When the trumpet is sounded again, they will be raised back to life.

According to the Qur'an, man is made the master of the earth. Human beings form a species different from animals, jinn and angels. While Satans are disobedient to Allah, angels do His bidding without any hesitation. Man can choose to do either. Hence, he is accountable for what he chooses to do. He has been placed in charge of the earth and required to build it. By building the earth, we mean building a happy human life, following Allah's guidance as explained by the prophets and messengers sent by Allah.

It is an essential characteristic of human beings to seek comfort and to obtain what gives pleasure. This applies to all spheres of life. Besides, Islam acknowledges this and does not consider it in any way undesirable as long as its satisfaction does not involve disobedience to God. In the Qur’an we read:

"Say: ‘Who is there to forbid the beauty which God has brought forth for His creatures, and the good things from among the means of sustenance’?"

This rhetoric question implies that anyone who forbids such beauty, adornments, luxuries and comforts has no justification, as long as enjoying such matters does not involve anything forbidden.

In fact the opposite is true. When God bestows some blessings and comforts on one of His servants, He likes to see that person enjoying that blessing, and loves to see him or her acknowledging God’s grace and doing what expresses gratitude to God for bestowing it.

Thus if a person is given plenty of money, then God likes to see him giving his family a comfortable living, including a good house and plenty of provisions. However, God would also love to see that person giving out his zakah and helping poor people and his community in other ways as well.

The answer to your question is given by the Prophet himself, peace be upon him, who says: "Every loan that brings the creditor a benefit is forbidden." What is proposed here is that in return for making a further advance, you will be receiving the rest that the family gets from a room they are letting. This is not in part settlement of the loan, but a clear benefit to you for only making the loan. This is benefit, which you would not have got without giving that loan. It is then directly related to the loan you are giving. Hence it is forbidden.

You do not need to stretch your mind far in order to determine this. What you will be getting is over and above the amount you are advancing. Hence it is usury. This is no doubt about it. You say that if you invest the amount of money you will be giving them, your investment will bring you an income that is greater than the rent you will be receiving. This may be true, but for an investment to be lawful from the Islamic point of view, it has to involve a risk of loss. If you invest the money in a business, you may incur a loss, while in the proposed arrangements you are certain of a gain. Besides, if you invest your money, you may get profits, but you will not get a reward from God for helping relatives in need, as you are bound to get if you lend the money to your in-laws without expecting anything over and above the return of the amount advanced.