Below is an e-mail from 4 December 2011 from a well meaning questioner named Ryan. It was on the question of salvation and the basis of what Muslims understand salvation to be and the only way one might be safe from Eternal Judgement. I hope that all readers find benefit in the answer:
I wanted to know what Muslims have to be sure that they are saved when they do not subscribe to the doctrine of original sin or a high priest as we have in our Lord Jesus Christ. I don’t want polemics but rather just a simple exposition of your faith. Thank you
Thank you for typing your message to HTS Publications after taking a look at our downloads. The website is specifically designed to cater to the needs of those who are trapped in either cults or false religions. Those of us who have worked on the site seek to follow the way of the Orthodox believers by preaching the faith with frankness and a generous heart.
We noticed that the faith of salvation had been hijacked and at times misrepresented by either schismatic sheep or well meaning Orthodox believers who were ill-equipped to deal with the matters that were challenging them. This in turn led to more confusion, so we decided to try to call back to the way of the Orthodox Fathers.
The first matter that every believer must understand is the matter of salvation. Salvation comes from the Arabic word Najah, which means, ‘unearned, unmerited salvation from the Eternal Fire and safety and admittance into the Paradise,’ which is indeed by the Mercy of Allah.
The Lord has mentioned salvation when he said,
“My people! What is the matter that I call you to salvation and you call me to the Fire. You call me to disbelieve in and to associate partners with Him that I have no knowledge of at all. I however invite you to the Almighty, the All-Forgiving.” 
The Prophet Muhammad, peace and blessings be upon him, stated,
“No one of you will be saved by his deeds, but by the Mercy of Allah.” 
Thus we understand that we are not simply barging into the Paradise, but that we are admitted by the Mercy of Allah from His Salvation. This matter is very important and has to be stressed. Why is it that we are not able to enter the Paradise by our deeds? It is simply due to the fact that our deeds are 1) not good enough and 2) are not even valid unless one is saved.
The Lord has said about the ineffectiveness of deeds such as sacrifices of meat and offerings for salvation,
Say, ‘It is neither their meat nor their blood that reaches Allah, but it is the piety from you that reaches Him.
Our Lord has spoken about the ineffectiveness of deeds through other people for salvation,
Our Lord has spoken about the ineffectiveness of working good deeds and being a good person,
Those who do not believe, their deeds are like a mirage in a sandy desert. Those taking part in it think they will find refreshment and water, until when they come to it, they find nothing but Allah waiting to give them their account – and Allah is swift in taking account.
None of these ways is sufficient to be saved in the sight of our Lord. It is only through His Word and Testimony of salvation that one might be saved,
Know that there is no god but Allah, then ask forgiveness for your sin.
We find here that the Lord has said first to bear witness to the testimony of faith La ilaha illallah, there is no god but Him. But there is a second part of the sentence, which is,
Muhammad is the Messenger of Allah.
Thus the sentence, ‘There is no god but Allah and Muhammad is the Messenger of Allah’ is the testimony of salvation. There is no salvation under any other way or testimony. Someone once asked the Prophet Muhammad, peace and blessings be upon him, after the death of his uncle, “What is salvation?” He answered, “Salvation is to believe in the word that my uncle had rejected today.” 
This lofty belief must be stated with conviction and its’ implications understood by the one seeking the relationship with the Lord.
What are some of the outcomes of believing in the testimony of faith in the life of a believer? They are the following,
A direct relationship with the Lord Everlasting
Our Lord has said,
When My slaves ask you about Me, indeed I am Near.
He has also said further,
Indeed He is the All Hearing, the Near.
Being given the promise of seeing the Most Merciful in the Hereafter.
Allah, the Almighty, has said the following,
Faces that day will be radiant, looking at their Lord.
This promise is made some 11 or more times in the Word of Allah (the Qur’an) as well as the Sunnah of His Messenger Muhammad, peace and blessings of Allah be upon him.
Salvation from eternal judgement and admittance into the Paradise
You who believe! fear Allah as is His Right to be feared and do not die except as Muslims. Hold fast to the rope of Allah and do not become divided. Remember the favour of Allah upon you when you were enemies and then by His Favour he put love between your hearts and made you brothers. You were on the very edge of the pit of the Fire and He gave you salvation from it.
Forgiveness of sins along with continuous cleansing of sins with righteous deeds committed thereafter
Allah will exalt those among you who believe who have knowledge in ranks. Allah knows everything you do.
This is also further stated by Allah when He proclaims,
Righteous deeds wipe out evil deeds.
Further, as a believer, you will want to obey Allah and do things pleasing to Him. Believers do good deeds because Allah saved them, not to become saved. Your obedience shows that you are in a committed relationship,
Say, “If you love Allah, then follow me. Allah will love you and forgive your sins. Allah is Forgiving, Merciful.” Say, “Obey Allah and Obey the Messenger. Allah does not love the unbelievers.”
Thank you again for contacting me and may the Lord richly bless you with sound faith and salvation.
Al-Hajj Abu Ja`far Al-Hanbali
 Surah Ghafir (40), ayah 41
 Collected by Imam Muslim ibn al-Hajjaj in his Al-Jami` us-Sahih, Book of the Description of the Day of Resurrection, the Paradise and the Fire, chapter, No One is Entering Paradise Because of His Deeds but by the Mercy of Allah, and classed by him as authentic.
 Surat ul-Hajj (22), ayah 37
 Surat un-Najm (53), ayat 37-39
 Surat un-Nur (24), ayah 39
 Surah Muhammad (47), ayah 19
 Surat ul-Fath (48), ayah 29
 Collected by Imam Ahmad ibn Hanbal in his Musnad, hadith #21 and classified by him as authentic.
 Surat ul-Baqarah (2), ayah 186
 Surah Saba (34), ayah 50
 Surat ul-Qiyamah (72), ayat 22-23
 Surah Ali Imran (3), ayat 102-103
 Surat ul-Mujadilah (58), ayah 11
 Surah Hud (11), ayah 114
 Surah Ali Imran (3), ayat 31-32