The Six Articles of Faith (Iman) are:

#1 Belief in God, #2 Belief in Angels, #3 Belief in Prophets/Messengers, #4 Belief in the Sacred Books, #5 Belief in Life After Death & Judgment Day, and #6 Belief in Divine Decree (Allah’s will).

#1 Belief in One God - Allah (Tawheed)

Islam upholds strict monotheism and belief in God forms the heart of their faith.  Islam teaches belief in one God who neither gives birth nor was born Himself (no trinity), and has no share in His caretaking of the world.  He alone gives life, causes death, brings good, causes affliction, and provides sustenance for His creation.  God in Islam is the sole Creator, Lord, Sustainer, Ruler, Judge, and Savior of the universe.  He has no equal in His qualities and abilities, such as knowledge and power.  All worship, veneration and homage is to be directed to God and none else.  Any breach of these concepts negates the basis of Islam.[i] 

 #2 Belief in Angels (Malaika)

Adherents to Islam must believe in the Unseen world as mentioned in the Quran.  From this world are the angels, emissaries of God, each assigned with a specific task. They have no free-will or ability to disobey; it is their very nature to be God's faithful servants. Angels are not to be taken as demigods or objects of praise or veneration; they are mere servants of God obeying His every command. (ibid)

 #3 Belief in Prophets and Messengers (from Adam up to Muhammad pbut)

Islam is a universal and inclusive religion.  Muslims believe in the prophets, not just the Prophet Muhammad, may God praise him, but the Hebrew prophets, including Abraham and Moses, as well as the prophets of the New Testament, Jesus, and John the Baptist.  Islam teaches God did not send prophets to Jews and Christians alone, rather He sent prophets to all nations in the world with one central message: worship God alone.  Muslim must believe in all prophets sent by God mentioned in the Quran, without making any distinction between them.  Muhammad was sent with the final message, and there is no prophet to come after him.  His message is final and eternal, and through him God completed His Message to humanity. (ibid)

#4 Belief in Sacred Texts (Torah, Books of Abraham, Psalms, Gospel of Jesus, and Qur’an)

 Muslims believe in certain books that God has sent down to humanity through His prophets.  These books include the Books of Abraham, the Torah of Moses, the Psalms of David, and the Gospel of Jesus Christ.  These books all had the same source (God), the same message, and all were revealed in truth.  This does not mean that they have been preserved in truth.  Muslims (and many other Jewish and Christian scholars and historians) find that the books in existence today are not the original scriptures, which in fact have been lost, changed, and/or translated over and over again, losing the original message. 

As Christians view the New Testament to fulfill and complete the Old Testament, Muslims believe that the Prophet Muhammad received revelations from God through the angel Gabriel to correct human error that had entered into the scriptures and doctrine of Judaism, Christianity and all other religions.  This revelation is the Quran, revealed in the Arabic language, and found today in its pristine form.  It seeks to guide mankind in all walks of life; spiritual, temporal, individual and collective.  It contains directions for the conduct of life, relates stories and parables, describes the attributes of God, and speaks of the best rules to govern social life.  It has directions for everybody, every place, and for all time.  Millions of people today have memorized the Quran, and all copies of the Quran found today and in the past are identical.  God has promised that He will guard the Quran from change until the end of times, so that Guidance be clear to humanity and the message of all the prophets be available for those who seek it. (ibid)

#5 Belief in Life after Death & Judgment Day (Youm al-Qiyamah)

About Judgment Day:

Muslims believe that a day will come when all of creation will perish and resurrected in order to be judged for their deeds: The Day of Judgment.  On this day, all will gather in the presence of God and each individual will be questioned about their life in the world and how they lived it.  Those who held correct beliefs about God and life, and followed their belief with righteous deeds will enter Paradise, even though they may pay for some of their sins in Hell if God out of His Infinite Justice chooses not to forgive them.  As for those who fell into polytheism in its many faces, they will enter Hellfire, never to leave there from. (ibid) 

Our good deeds and bad deeds are written down by the Angels that have been assigned with us. And these good and bad deeds are weighed on the Day of Judgment. If the good deeds outweigh the bad ones, then one will be admitted to Paradise. If bad deeds outweigh the good ones, then this person (if God doesn't forgive him) will be admitted to Hellfire for a period, and then come out of it, to go to Paradise. If one has good deeds as equal as bad deeds, then such a person will be held for a while in a place between Paradise and Hellfire, but finally will end up in Paradise by the grace of God.

 About Life After Death:

The dead have a continued and conscious existence of a kind in the grave.  Muslims believe that, upon dying, a person enters an intermediate phase of life between death and resurrection.  Many events take place in this new “world”, such as the “trial” of the grave, where everyone will be questioned by angels about their religion, prophet, and Lord.  The grave is a garden of paradise or a pit of hell; angels of mercy visit the souls of believers and angels of punishment come for the unbelievers.

Resurrection will be preceded by the end of the world.  God will command a magnificent angel to blow the Horn.  At its first blowing, all the inhabitants of the heavens and the earth will fall unconscious, except those spared by God, and the earth will face great dramatic changes.

People will be resurrected into their original physical bodies from their graves, thereby entering the third and final phase of life.  The Horn will blow again upon which people will rise up from their graves, resurrected!

God will gather all humans, believers and the impious, jinns, demons, even wild animals. It will be a universal gathering. The angels will drive all human beings naked, uncircumcised, and bare-footed to the Great Plain of Gathering. People will stand in wait for judgment and humanity will sweat in agony. The righteous will be sheltered under the shade of God's Magnificent Throne. When the condition becomes unbearable, people will request the prophets and the messengers to intercede with God on their behalf to save them from distress.

The balances will be set and the deeds of men will be weighed. Disclosure of the Records of the deeds performed in this life will follow. The one who will receive his record in his right hand will have an easy reckoning. He will happily return to his family. However, the person who will receive his record in his left hand would wish he were dead as he will be thrown into the Fire. He will be full of regrets and will wish that he were not handed his Record or he had not known it. Then God will judge His creation. They will be reminded and informed of their good deeds and sins. The faithful will acknowledge their failings and be forgiven. The disbelievers will have no good deeds to declare because an unbeliever is rewarded for them in this life. Some scholars are of the opinion that the punishment of an unbeliever may be reduced in lieu of his good deeds, except the punishment of the great sin of disbelief.

The Siraat is a bridge that will be established over Hell extending to Paradise. Anyone who is steadfast on God's religion in this life will find it easy to pass it. Paradise and Hell will be the final dwelling places for the faithful and the damned after the Last Judgment. They are real and eternal. The bliss of the people of Paradise shall never end and the punishment of Unbelievers condemned to Hell shall never cease. [i]

#6 Belief in Divine Decree / Predestination / Fate (Qadr)

Islam asserts that God has full power and knowledge of all things, and that nothing happens except by His Will and with His full knowledge.  What is known as divine decree, fate, or "destiny" is known in Arabic as al-Qadr.  The destiny of every creature is already known to God. 

This belief however does not contradict with the idea of man's free will to choose his course of action.  God does not force us to do anything; we can choose whether to obey or disobey Him.  Our choice is known to God before we even do it.  We do not know what our destiny is; but God knows the fate of all things.[1]

Man has free will and choice by means of which he does some things and refrains from others, and he believes or disbelieves, and he obeys or disobeys, for which he will be brought to account and rewarded or punished, although Allaah knows what he will do, what he will choose and what his ultimate destiny will be. But Allaah does not compel him to do evil, or to choose kufr, rather He clearly shows him the path and He has sent Messengers and revealed Books, and shown him the right way. Whoever goes astray does so to his own loss.[ii]

“And say: “The truth is from your Lord.” Then whosoever wills, let him believe; and whosoever wills, let him disbelieve” Qur’an 18:29

 

Suggested Reading:

Collection of Articles about the Hereafter (Heaven & Hell)