Note 1 at Joh 13:33: Jesus was speaking to His disciples of His death, less than twenty-four hours away. Jesus had repeatedly told His disciples of His death and His victory in resurrection (see note 1 at Mt 16:21) so that their hearts would not be troubled (Joh 14:1). But the disciples didn't understand and suffered needless agony during Christ's three days in the grave.

Likewise, the Lord has given us everything that pertains to life and godliness through the knowledge of His Word (2Pe 1:3-4) so that there is no excuse for the anxiety we as Christians many times experience. We just need to believe God's Word. We need to pray that the Lord would open our understanding that we might understand the Scriptures (Lu 24:45).