Lukewarm Christians are in trouble with Messiah Jesus. Paul warned they would abound in the last days.
1But understand this: In the last days terrible times will come. 2For men will be lovers of themselves, lovers of money, boastful, arrogant, abusive, disobedient to their parents, ungrateful, unholy, 3unloving, unforgiving, slanderous, without self-control, brutal, without love of good, 4traitorous, reckless, conceited, lovers of pleasure rather than lovers of God, 5having a form of godliness but denying its power. Turn away from such as these!2 Timothy 1:1-5
In his letters to the churches, Jesus identified lukewarm Christians in Laodicean type churches and sternly exhorts them.
14To the angel of the church in Laodicea write:
These are the words of the Amen, the faithful and true Witness, the Originator of God’s creation.
The Amplified Bible puts verse 15-16: “I know your deeds, that you are neither cold (invigorating, refreshing) nor hot (healing, therapeutic); I wish that you were cold or hot. So because you are lukewarm (spiritually useless), and neither hot nor cold, I will vomit you out of My mouth [rejecting you with disgust].”
Jesus rejects lukewarm Christians because they are not a pleasing temperature. They are not cold enough to be invigorated with the power of His Spirit. They are tepid instead of fired up for Jesus. His spiritual fire does not burn in their bones.
Jesus rebukes lukewarm Christians for their me attitude and wretched spiritual state, then counsels them to partake of his divine nature.
17You say, ‘I am rich; I have grown wealthy and need nothing.’ But you do not realize that you are wretched, pitiful, poor, blind, and naked. 18I counsel you to buy from Me gold refined by fire so that you may become rich, white garments so that you may be clothed and your shameful nakedness not exposed, and salve to anoint your eyes so that you may see. 19Those I love, I rebuke and discipline. Therefore be earnest and repent.
20Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in and dine with him, and he with Me. 21To the one who overcomes, I will grant the right to sit with Me on My throne, just as I overcame and sat down with My Father on His throne.
22He who has an ear, let him hear what the Spirit says to the churches.” Revelation 3:17-22 BSB (Col 2:1–5; 1 John 3:11-23)
How to make your calling and election sure.
1 Simon Peter, a servant and emissary of Yeshua the Messiah,* to those who have obtained a like precious faith with us in the righteousness of our God and Savior, Yeshua the Messiah: 2 Grace to you and peace be multiplied in the knowledge of God and of Yeshua our Lord, 3 seeing that his divine power has granted to us all things that pertain to life and godliness, through the knowledge of him who called us by his own glory and virtue, 4 by which he has granted to us his precious and exceedingly great promises; that through these you may become partakers of the divine nature, having escaped from the corruption that is in the world by lust. 5 Yes, and for this very cause adding on your part all diligence, in your faith supply moral excellence; and in moral excellence, knowledge; 6 and in knowledge, self-control; and in self-control, perseverance; and in perseverance, godliness; 7 and in godliness, brotherly affection; and in brotherly affection, love. 8 For if these things are yours and abound, they make you to not be idle or unfruitful in the knowledge of our Lord Yeshua the Messiah. 9 For he who lacks these things is blind, seeing only what is near, having forgotten the cleansing from his old sins. 10 Therefore, brothers,† be more diligent to make your calling and election sure. For if you do these things, you will never stumble. 11 For thus you will be richly supplied with the entrance into the eternal Kingdom of our Lord and Savior, Yeshua the Messiah. 2 Peter 1:1-11 BSB