Answer: God will bring about the appearing of our Lord
Jesus Christ in His Own time, (verses 14 and 15).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
Matthew 24:36-44: [Jesus said,] "No
one knows about that day or hour, not even the angels in heaven,
nor the Son, but only the Father. As it was in the days of
Noah, so it will be at the coming of the Son of Man. For in
the days before the flood, people were eating and drinking,
marrying and giving in marriage, up to the day Noah entered the
ark; and they knew nothing about what would happen until the flood
came and took them all away. That is how it will be at the coming
of the Son of Man. Two men will be in the field; one will be
taken and the other left. Two women will be grinding with a hand
mill; one will be taken and the other left. Therefore keep
watch, because you do not know on what day your Lord will
come. But understand this: If the owner of the house had
known at what time of night the thief was coming, he would have
kept watch and would not have let his house be broken into.
So you also must be ready, because the Son of Man will come at an
hour when you do not expect Him."
Matthew 24:50: [Jesus said,]
"The master of that servant will come on a day when he does
not expect him and at an hour he is not aware of."