You do greatly err, not knowing what Jesus taught.
Matthew 24
[42] Watch therefore: for ye know not what hour your Lord doth come.
[43] But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up.
[44] Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.
Oh you are suck a knowledgeable and righteous person. You can quote scripture to shame a person into your way of believing. You believe that all people who believe they are "Christian" have a good working understanding of the Scriptures.
Does not God tell us to study all of the scriptures, if you had read on then you would have also understood the following was also applicable to all Christians concerning the coming of the Lord. Let us consider the context of the wider passage where your quote was found: -
Matt. 24:36-51: - No One Knows the Day or Hour
(Mark 13:32-37; Luke 17:26,27,34,35; 21:34-36)
36 "But of that day and hour no one knows, not even the angels of heaven, but My Father only. 37 But as the days of Noah were, so also will the coming of the Son of Man be. 38 For as in the days before the flood, they were eating and drinking, marrying and giving in marriage, until the day that Noah entered the ark, 39 and did not know until the flood came and took them all away, so also will the coming of the Son of Man be. 40 Then two men will be in the field: one will be taken and the other left. 41 Two women will be grinding at the mill: one will be taken and the other left. 42 Watch therefore, for you do not know what hour your Lord is coming. 43 But know this, that if the master of the house had known what hour the thief would come, he would have watched and not allowed his house to be broken into. 44 Therefore you also be ready, for the Son of Man is coming at an hour you do not expect.
The Faithful Servant and the Evil Servant
(Luke 12:41-48)
45 "Who then is a faithful and wise servant, whom his master made ruler over his household, to give them food in due season? 46 Blessed is that servant whom his master, when he comes, will find so doing. 47 Assuredly, I say to you that he will make him ruler over all his goods. 48 But if that evil servant says in his heart, 'My master is delaying his coming,' 49 and begins to beat his fellow servants, and to eat and drink with the drunkards, 50 the master of that servant will come on a day when he is not looking for him and at an hour that he is not aware of, 51 and will cut him in two and appoint him his portion with the hypocrites. There shall be weeping and gnashing of teeth.
NKJV
What does it mean for us to be ready for when the Son of Man will Come?
What is the preparation that we must do to be ready?
We can only be ready when we have renewed our hearts and put on the personhood of who God intended us to be from the beginning of time. The Parable of the separation of the sheep from the Goats in the next chapter suggests that the ones that will remain in God's presence are the one who have taken on board God's heart and become His good servants in teaching those around them God's food in due season so that when Christ comes they will remain in His presences after that time and not be dispatched into the Lake of Fire.
We all should be focusing on being God's Good Servants rather than being concerned about when He will be coming for His Second Advent.
Shalom