Question: "What does it mean that the love of many will grow cold (Matthew 24:12)?"
Answer: Jesus predicted that the love of many would grow cold as part of His answer to the disciples’ question, “What will be the sign of your coming, and of the end of the age?” In Matthew 24, in the Olivet Discourse, Jesus describes the end of the age that will precede His second coming. He says that there will be false Christs (verse 5), wars (verse 6), and strife and natural disasters (verse 7).
Jesus also warned of the persecution of believers, some of whom would prove to be false disciples who would turn on one another (Matthew 24:9–10). “And,” Jesus said, “because lawlessness will be increased, the love of many will grow cold” (verse 12, ESV). Whether it is because of the deluding influence of the false teachers or the persecution or the fear of death, the zeal of many false professors will diminish. Their love toward God and toward the church will “grow cold.” True Christians, even those whose faith is weak, will persevere to the end (verse 13). Theirs is the true love, which is the fruit of the Holy Spirit (Galatians 5:22), and it cannot fail (1 Corinthians 13:7). True love cannot become cold because it is sustained by Christ who is able to keep us from falling (Jude 1:24).
For those without the Spirit, however, what love they do have will become colder and colder in the last days. Paul expands this idea in 2 Timothy 3:1–4 when he describes the last days. The love those people have is not a warm, living love for God and His truth and His people. Rather, it is the love of self and the love of money (verse 2). Paul describes those whose love for God, Christ, and the saints is only in pretense, not in reality. They do all they do in a religious way from self-love and to selfish ends. Their aim is to gain glory and applause from men or to use religion to gain something for themselves. They do nothing for the glory of God, the honor of Christ, or the good of others.
How can we be sure that the love we have for Christ will never grow cold? We begin by examining ourselves to be sure we are truly in the faith (2 Corinthians 13:5). If we truly belong to Christ, we can be confident that we possess the love from the Spirit that never grows cold. Then we should make every effort to increase our love: “This is my prayer: that your love may abound more and more in knowledge and depth of insight, so that you may be able to discern what is best and may be pure and blameless for the day of Christ, filled with the fruit of righteousness that comes through Jesus Christ—to the glory and praise of God” (Philippians 1:9–11).