Mark 13:7

And when ye hear of wars, and rumors of wars, be not troubled; they must come to pass; but not yet is the end.

Matthew 18:7

Woe to the world because of stumblingblocks! For it must needs be that stumblingblocks come; but woe to the man through whom the stumblingblock cometh!

Matthew 24:6-7

And ye are to hear of wars, and rumors of wars; see that ye be not troubled; for these things must come to pass; but not yet is the end.

Luke 21:9-11

And when ye hear of wars and tumults, be not terrified; for these things must first come to pass; but not immediately is the end.

John 14:1

Let not your heart be troubled. Have faith in God, and have faith in me.

John 14:27

Peace I leave with you; my peace I give to you; not as the world giveth, do I give to you. Let not your heart be troubled, nor let it be afraid.

Acts 17:3

explaining them, and setting forth that it was necessary for the Christ to suffer, and to rise from the dead, and that "this is the Christ,Jesus whom I am making known to you."

Treasury of Scripture Knowledge

Summary

And when ye shall hear of wars and rumours of wars, be ye not troubled: for such things must needs be; but the end shall not be yet.

Bible References

When

Matthew 24:6
And ye are to hear of wars, and rumors of wars; see that ye be not troubled; for these things must come to pass; but not yet is the end.
Luke 21:9
And when ye hear of wars and tumults, be not terrified; for these things must first come to pass; but not immediately is the end.
John 14:1
Let not your heart be troubled. Have faith in God, and have faith in me.

Must

Matthew 18:7
Woe to the world because of stumblingblocks! For it must needs be that stumblingblocks come; but woe to the man through whom the stumblingblock cometh!
Acts 17:3
explaining them, and setting forth that it was necessary for the Christ to suffer, and to rise from the dead, and that "this is the Christ,Jesus whom I am making known to you."