The short answer is that nobody knows how long it will be before Jesus returns. However, we do have many signs in the world today that demonstrate that the time for his return must be near. Bible prophecy concerning the conditions of the world at the time of his return seem to exactly describe the condition of the world in our day and age.
Here is some information from the website which I am sure you will find useful in helping you with this question:
Also, you would benefit if you sign up for our free Bible study course available on the website. You may take the course online or by mail. Go to https://www.thisisyourbible.com
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God bless and keep you,