Islam IS the true religion of humanity.

[WesOlsen]

How do you know there is a God and how do you know there is just one God and not multiple ones?

The miracles of Allah are all around us. Jinn( his other creations) are also existent. I can't bring Him in front of anybody, only He can summon everybody on His will.

Define Greatest. Greatest in what sense?
The Most Majestic. The Most Exalted. The Most Wise. There is nothing greater or more powerful than the Creator as everything is His creation.

First of all how do you know he is merciful and what do you base that assessment on?
113 out of 114 of the Holy Quran begin with Bismillah-hir-Rahman-nir-Rahim ( "In the name of Allah, Most Gracious, Most Merciful" )

Quran 5:74
"So will they not repent to Allah and seek His forgiveness? And Allah is Forgiving and Merciful."

Quran 21:47 "And We place the scales of justice for the Day of Resurrection, so no soul will be treated unjustly at all. And if there is [even] the weight of a mustard seed, We will bring it forth. And sufficient are We as accountant."
Every thing will come into account. Allah does not forget even the smallest of good deeds, those that even have the weight of a mustard seed.

Quran 39:53
Say, "O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah . Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.""
Allah can forgive all and any type of sins if the sincerity is there. There is always a chance.

Many people on this Earth when you commit a wrong they will bring it up later. Allah forgives and gives you multiple chances. He is the Most Merciful. Wow

What do you mean by saying that I am still in his hands? That he can see my future? Or something else?
Your life is always in His hands. He can take it away if he likes. He knows your future. You don't exist independent of Him. You are His creation as we all are.

So should we try to prevent evil from happening or should we not? Because if we do we interfere with Gods test of that person we are trying to prevent evil happening to.
Also what is the purpose of this test?
You're supposed to take a stand against tyranny always. You don't let a tyrant do whatever he/she wants. Allah does not create evil.

If you're a good person you will most likely go to heaven...except those that are atheists.
Atheists reject Allah, and Allah deals with the disbelievers strictly and justly.
Atheists on here have save the worst types of names, there is no place for that nor are they on the level of any of the righteous.

First of all why do you say "most likely" don't you know for sure if good people will go to heaven or not?
Those who are righteous do not have to worry. It would be not in any person's place to set a guarantee as he is not the one who decides. Only Allah sets absolutes. If I say you will go to heaven, it doesn't matter what I say but only what Allah says and if you are righteous most likely Allah will allow that person into heaven

On what conditions do people go to heaven?
Good deeds, belief in God( Jews, Christians, Sabeans, maybe others as only Allah is Most Wise and Most Merciful)


How is it religion of science when in science you take nothing on faith but must prove things?
Islam encourages gaining knowledge, advancements in science for the benefit of humanity and the Quran has science references as well though it is not a textbook. It a Book to guide humanity.

---

It's up to you to buy a Quran, read it for yourself and visit a local mosque preferable one that is a Shia mosque.

and

That is the habit of the deceitful. Attempt to use long paragraphs to stay in denial of the truth.

lol