John 16:33, Amplified Bible;

"I have told you these things, so that in Me you may have [perfect] peace and confidence.

In the world you have tribulation and trials and distress and frustration; but be of good cheer [take courage; be confident, certain, undaunted]!

For I have overcome the world.
[I have deprived it of power to harm you and have conquered it for you.]"