One should never follow assumption, because that leads to chaos. When one is uncertain, the doubtful comes into play and one can be led very far astray. And upon that, others may be led astray as well.
Indeed, those who follow assumption avail not against the truth. The truth is like light. The darkness of assumption is many.
And most of them follow not except assumption. Indeed, assumption avails not against the truth at all. Indeed, Allah is Knowing of what they do. (Qu’ran 10:36)
When things are doubtful, one should leave it. Things that are straight and clear are concise and to the point. One should avoid the uncertain things. The things that make one doubt. The things that make one waver in one’s heart.
“Righteousness is good character, and sin is that which wavers in your heart and which you do not want people to know about." –Prophet Muhammad (SWS)
The things that are certain are as clear as the sun. You can see it like you see the blue sky. You can see it as you see the green trees. They destroy the shadows of doubt. But remember, too much knowledge can be overpowering. You don’t want to be blinded by the shining light that is too powerful.
For example, you could want to learn about the current civil strife a country might be undergoing. Knowledge is empowering, but knowing about the truth might lead to ugly things. It might lead to seeing the corpses of hundreds in the fray of war. It might be blinding because the truth is too powerful. Your young eyes may be too virgin to yield to that.
Another example might be trying to know why a friend hurt you. To know too much is to wonder why he would do something, and what you might find is ugly. But the darkest part of it all is assuming. You don’t want to assume that he did this because he inherently hates you. Nor do you want to assume that he’s out to get you. You will begin to then bask in your own dark assumptions, leading you to a multitude of paths of evil.
When you sit there and try to figure everything out yourself, you might follow the whispers in your mind that only lead you to a fog of uncertainty. You won’t know where the path leads in front of you, and before you know it, you won’t be able to see your feet in front of you. You won’t be able to know which way is which, or where you’re being led. You don’t feel on level ground because you’re basing things off of something you just theorized.
To string a conclusion off the little evidences you have is fruitless. That’s why you wait. You wait for the answer to come to with the most powerful tool man can have: patience.
"Whoever seeks chastity Allaah will make him chaste, and whoever seeks help from none but Allaah, He will help him, and whoever is patient He will make it easy for him, and no one has ever been given anything better than patience." –Prophet Muhammad
With patience, the light of day will eventually destroy the darkness of night. The certainty will eventually destroy the unborn assumptions before they birth. You will see the reality of that which you were uncertain about.
And you might see that that friend was doing this for your own good. That maybe, he knew himself that he would be a burden, so he left you for the sake of your own good. Indeed, things change.
So wait for the fog of uncertainty to dissipate. One day, all things will be made clear.
Or do you feel secure that He who [holds authority] in the heaven would not send against you a storm of stones? Then you would know how [severe] was My warning. (Qu’ran 67:17)