There may be many causes of this condition. I believe our Western Church culture is partly to blame. Also, incorrect teaching, cessationalism (unbelief in gifts of the Holy Spirit), disbelief in general, lack of growth, etc. Or somehow the person just allowed the world to become his or her idol.
The writer of Hebrews is very tough on what he calls spiritual sluggards. In Chapter 5 he comes down quite hard on his readers by telling them they are still babies in Christ when they should be adults by now. He goes on in Chapter 6 to warn them that if they walk away from Jesus and the Gospel and reject their faith, there's no way to come back. I bet you haven't heard that in church lately?
If they then deviate from the faith and turn away from their allegiance—it is impossible to bring them back to repentance Hebrews 6:6
Basically, the writer of Hebrews is warning people to not be spiritual sluggards because it could lead to full out rejection of the faith. The good news is, he gives the solution toward the end of the chapter. And that solution is Hope.
But we do strongly and earnestly desire for each of you to show the same diligence and sincerity all the way through in realizing and enjoying the full assurance and development of your hope until the end, In order that you may not grow disinterested and become spiritual sluggards 11-12
I'm thinking Hope plays a pretty important part in keeping us focused on God and the things above instead of getting distracted by the world. But Hope in what?
I spent some time looking up Hope in the New Testament and listed some of the verses below. It seems to me that the Hope the writer is speaking of is the Hope of Heaven, the Hope of the resurrection, the Hope of eternal life, the Hope of the next age. The Hope of Jesus coming again! Read through the verses and see for yourself.
Yet I rarely meet a fellow Christian who is excited about Jesus's return. Most don't know much about it, or don't want to know much about it. Some like to argue about the timing, others are afraid of it. Some are just too caught up in the here and now to think about the future, let alone eternal life or heaven. Some even hope His coming is delayed because there's things they want to do first! When I try to bring up my excitement about end times and the second coming, they look at me funny and label me one of those prophecy nuts.
But what the heck is the Gospel message for then? Is it just a message that we should be kind and love each other and try not to sin? Offer a prayer now and then and hope God is listening? Or is it a message that we are not of this world, that there is something beyond this place where we will live forever in the presence of God and experience things so wonderful our minds can't even conceive of them? Isn't that the hope of salvation through Jesus?
Listen to Paul's take on Christianity without the hope of eternal life in Heaven.
If in this life only we have hope in Christ, we are of all men the most pitiable. 1 Corinthians 15:19
In other words, if you don't have hope in Heaven, in eternal life, and the next age, you should be pitied because without that, following Jesus in this world would be nothing but difficult with no reward.
Feeling a little sluggish lately? Try this. Search the Scriptures for all the promises describing Heaven and eternity, describing our inheritance in Jesus, prophesying His soon return, and study them. Meditate on them and what it will be like in the next age, what it will be like to walk in the garden with God like Adam and Even did... in a paradise beyond your wildest dreams. If that doesn't get you excited about Jesus and desiring to know Him more and walk with Him more closely, nothing will!
Men and brethren, I am a Pharisee, the son of a Pharisee; concerning the hope and resurrection of the dead I am being judged!” Acts 23:6
I have hope in God, which they themselves also accept, that there will be a resurrection of the dead, both of the just and the unjust Acts 24:15
Not only that, but we also who have the firstfruits of the Spirit, even we ourselves groan within ourselves, eagerly waiting for the adoption, the redemption of our body. For we were saved in this hope, but hope that is seen is not hope; for why does one still hope for what he sees? But if we hope for what we do not see, we eagerly wait for it with perseverance. Romans 8: 23-25
That you may know what is the hope of His calling, what are the riches of the glory of His inheritance in the saints Ephesians 1:18
because of the hope which is laid up for you in heaven, of which you heard before in the word of the truth of the gospel, Colossians 1:5
For what is our hope, or joy, or crown of rejoicing? Is it not even you in the presence of our Lord Jesus Christ at His coming? 1 Thess 2:19
looking for the blessed hope and glorious appearing of our great God and Savior Jesus Christ, Titus 2:13
Therefore gird up the loins of your mind, be sober, and rest your hope fully upon the grace that is to be brought to you at the revelation of Jesus Christ; 1 Peter 1:13