New American Standard Bible (©1995)
"Now I have told you before it happens, so that when it happens, you may believe.

International Standard Version (©2008)
I have told you this now, before I leave, so that when I do leave, you will believe.

GOD'S WORD® Translation (©1995)
"I'm telling you this now before it happens. When it does happen, you will believe.

King James Bible
And now I have told you before it come to pass, that, when it is come to pass, ye might believe.

American King James Version
And now I have told you before it come to pass, that, when it is come to pass, you might believe.

American Standard Version
And now I have told you before it come to pass, that, when it is come to pass, ye may believe.

Bible in Basic English
And now I have given you word of it before it comes, so that, when it comes, you may have faith.

Douay-Rheims Bible
And now I have told you before it comes to pass: that when it shall come to pass, you may believe.

Darby Bible Translation
And now I have told you before it comes to pass, that when it shall have come to pass ye may believe.

English Revised Version
And now I have told you before it come to pass, that, when it is come to pass, ye may believe.

Webster's Bible Translation
And now I have told you before it cometh to pass, that when it hath come to pass, ye may believe.

Weymouth New Testament
I have now told you before it comes to pass, that when it has come to pass you may believe.

World English Bible
Now I have told you before it happens so that, when it happens, you may believe.

Young's Literal Translation
And now I have said it to you before it come to pass, that when it may come to pass, ye may believe;