"In order to...", "To..." or "For..."

Solution 1:

"For passing" and "for finding" are not correct. "In order to" and "To" are correct, but I favour "To" because it is more concise:

To pass the exams, you have to study a lot.

To find the object in the database, users have to run a SQL query.

A more natural way of saying this is:

You have to study a lot to pass the exams.

Users have to run a SQL query to find the object in the database.

Solution 2:

According to BBC World Service, in order to "sounds a bit more formal and explicit" than to.

Solution 3:

"In order to" specifies that the phrase which follows it is not the subject of the sentence, prompting the reader to be on the lookout for the subject which occurs later in the sentence.

For example take the sentence "To err is human, to forgive, divine." In this sentence "To err" is the subject of the sentence, and cannot be replaced by "In order to err".

Now consider the sentence "In order to communicate the utility and safety of the product the most effective phraseology varies wildly depending on the target audience".

This could be replaced with "To communicate the utility and safety..." and remain grammatically correct, but the reader will initially assume that "To communicate" is the subject of the sentence since it is at the beginning. After reaching the phrase "the most effective phraseology" the reader will realize that this phrase was the subject of the sentence, and will need to go back and re-read the sentence with this new information. Adding "in order to" makes the sentence feel more natural and easier to read.