1 Thessalonians 5...
1Now, brothers, about times and dates we do not need to write to you,
2for you know very well that the day of the Lord will come like a thief in the night.
3While people are saying, "Peace and safety," destruction will come on them suddenly, as labor pains on a pregnant woman, and they will not escape.
4But you, brothers, are not in darkness so that this day should surprise you like a thief.
5You are all sons of the light and sons of the day. We do not belong to the night or to the darkness.
6So then, let us not be like others, who are asleep, but let us be alert and self-controlled.
7For those who sleep, sleep at night, and those who get drunk, get drunk at night.
8But since we belong to the day, let us be self-controlled, putting on faith and love as a breastplate, and the hope of salvation as a helmet.
9For God did not appoint us to suffer wrath but to receive salvation through our Lord Jesus Christ.
10He died for us so that, whether we are awake or asleep, we may live together with him. 11Therefore encourage one another and build each other up, just as in fact you are doing.
I believe "the day" refers to God's glory or Heaven where we will not need the sun because His glory will be our light. His LIGHT. That light that lives in our hearts, that burns within us. In the day of the Lord's return the "sons of the light" will be revealed...
Romans 8:18[ Future Glory ] I consider that our present sufferings are not worth comparing with the glory that will be revealed in us.
Romans 8:19The creation waits in eager expectation for the sons of God to be revealed.
So since we are sons of the day, we should put on the breastplate of faith and love-this means guarding our heart by continually believing God, and by loving Him and others. We are told that in the last days the love of most will grow cold. Probably due to the recurring offenses that we have to forgive in order to keep that light in our heart (keep it from growing cold). Also highlighted is the helmet of salvation, which is guarding our thoughts/ our mind. That means continually renewing it with the Word of God.
Romans 12:2 Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is—his good, pleasing and perfect will.
Ephesians 5: 25-27 Husbands, love your wives, just as Christ loved the church and gave himself up for her to make her holy, cleansing her by the washing with water through the word, and to present her to himself as a radiant church, without stain or wrinkle or any other blemish, but holy and blameless.
We notice in the above Thessalonians passage that "self-control" is used twice. In the King James Version, it is "sober". We must diligently guard these two vital areas in order for the light to continue to shine in the darkness mentioned.
Heavenly Father, our source of Light. You are the fire in our hearts, help us keep oil in our lamps, to keep the fire of your love burning bright in our hearts! Thank you that you are able to keep us blameless until that day by the blood of Jesus. Set our hearts on fire! In Jesus' brilliant name, amen.