Allah says:

Verily, Allah has purchased from the faithful believers their persons and their property; for theirs in return is the Garden of Paradise. (9:111)

A true believer in the hands of the Lord is like a slave in the hands of the master. Hence, the reason why the name Abd is attached to many names connected with the Attributes of Allah, e.g. Abdullah meaning the slave of Allah.

When we look at the literal meaning of the word slave we find that it means: A person who is the legal property of another; or others, and is bound to absolute obedience. (Oxford Concise Dictionary: topic slave)

The true meaning and application of the term in relation to believers can be found in the declaration of Father Abraham. He said:
Say: Truly, my prayer and my service of sacrifice; my life and my death are for Allah; the Cherisher of the Worlds; no partner has He. This I am commanded, and I am the first of those who bow to His Will. (6:162-163)

Total submission was demonstrated in the most perfect way by our beloved Leader and Allah's Messenger, Prophet Muhammad (peace be upon him). About him Allah says:

He does not say anything of his own desire. (53:3)

It is because of his total and complete submission to his Lord that Allah calls him His Abd. He says:

Glory be to Him Who transported His Slave on a Journey… (17:1)

Allah wants every true believer to realize that he and all his possession belong to Allah. So He has offered to purchase every thing for all who are willing to submit entirely to His Commands. He says: 

Those who rehearse the Book of Allah, establish regular Prayer, and spend out of what We have provided for them, secretly and openly, hope for a commerce that will never fail: (35:29)

The true believer does everything for the sake of Allah; that is a personal decision, as each individual has the choices of Allah or the material world. Some people choose the world instead of Allah. About them Allah says:

These are the people who purchase the life of this world at the price of the Hereafter. Their penalty shall not be lightened, nor shall they be helped. (2:86)

Those who invest all their assets on worldly benefits and pleasure do not take time to consider what Allah says in His Holy Words about material possessions. He says:

What is with you must vanish and what is with Allah will endure. And We will certainly bestow on those who patiently persevere their reward according to the best of their actions. (16:96)

Allah has given us numerous examples in the Holy Qur'an of those people who spent all their time amassing worldly assets and how in the end they had to leave it behind and move on, regretting about how they wasted their lives. He gave examples of Qarun, Haman and Pharaoh. He says:

Qarun, Pharaoh and Haman; there came to them Moses with Clear Signs, but they behaved with insolence on the earth; yet they could not over reach. Each one of them We seized for his crime; of them, against some We sent a violent tornado; some were caught by a blast; some We caused the earth to swallow up; and some We drowned. It was not Allah Who injured them; They injured their own souls. (29:39-40).

Such people selected to invest in things that were of little value to them just for a short while. About such people Allah says:

Those who purchase unbelief at the price of faith; not the least harm will they do to Allah; but they will have a grievous punishment. (3:177)

Allah invites the believers to do good business with Him. He says:

O you who believe, shall I lead you to a bargain that will save you from a grievous penalty. Believe in Allah, and His messengers; and that you strive your utmost in the cause of Allah; with your property and your persons. That is best for you if you only knew. (61:10)

For those who strive in His Cause; He says:

For He will pay them their wages; and give them more out of His Grace. Verily, He is Oft Forgiving, Most ready to appreciate (35:30)

Some people do not invest with Allah but they want profits and benefits from Him. They spend all their time with the commerce of the world; they do not think about giving Allah a gift in the form of charity to the needy; they do not take out a little time to thank Him for His favours and mercies; and they do not read His Holy Words. How will they face Him on that terrible day? May Allah bless the believers with the correct attitude of appreciation of His favours to them and willing submission to Him.