"In the end, the biggest problem with prosperity theology is not that it promises too much, but that it promises far too little"
First, what is the prosperity theology/gospel? It is teaching given by many pastors, authors and many TV preachers who use the Scriptures to state that God's wants each of His children to experience physical health and financial wealth. The corollary of this is that if His children are not experiencing this, there is a problem in their relationship with the Lord. The word 'gospel' is used since 'gospel' in the Greek means 'good news'. Christianity thus becomes the 'good news' of God's promise of your spiritual, physical and financial well being.
Secondly, we need to be aware that this is another 'cultural moment' we are experiencing in the history of Christianity, and is strikingly different to what has been preached over the centuries in the church. Today our religious expectations have piggy backed the gains of the world (which offers health and wealth to us all), and even if we do not hold to the prosperity teaching, at bottom most of us assume that if God had His way with us He would heal our bodies and fill our wallets. Are not most of our testimonies of God's work in our lives about how we have been provided for in these realms? His faithfulness or goodness commonly translate to mean health and wealth. This is also the reason why many people serve God and believe in Him: to be spared physical and financial suffering.
What Al Mohler was wanting to point out was that if we believe that our health and wealth are the main concerns of God in the Gospel of Jesus Christ, we have an impoverished perspective of His work and are missing the heart of what is on His agenda for our lives.
Traditionally (and correctly) God's main intent for us now in this life is not our health or wealth but our holiness, i.e., to be like Him. The greatest gift and the most urgent work of God is simply not physical blessing; This is clear to all in their most sane moments when they ponder what their greatest needs are. What is the greatest thing that a Christian would want for her children? Is it not to know Christ, and for them to reflect His character,and to live a life pleasing to God Almighty? Because of the fleeting and temporal nature of our present bodily experience, it is not ultimately their best life now that we want for those we love but their best life in eternity that we want for them! Does not the entire New Testament warn us that if we aim at beautify bodies and bounteous bank balances, we will move away the Gospel and not closer to it? Consider the words of Jesus in Mark 4:18-19 and also those of His apostle in 1 John 2:15-17:
Still others are like the seeds sown among the thorn bushes. These are the people who hear the word, but the worries of life, the deceitful pleasures of wealth, and the desires for other things come in and choke the word so that it can't produce a crop.
Stop loving the world and the things that are in the world. If anyone persists in loving the world, the Father's love is not in him. For everything that is in the world—the desire for fleshly gratification, the desire for possessions, and worldly arrogance—is not from the Father but is from the world. And the world and its desires are fading away, but the person who does God's will remains forever.
Of course we trust God for our provision in every area of our lives, and we ought to testify to His faithfulness in caring for us in the material areas of our lives. BUT, we must know that there is a higher purpose that He has with us in this life. He wants us to 'share His holiness' (Hebrews 12:10). His purpose is for us to be like Jesus (Romans 8:29). He want us to not settle for temporary things but rather be willing to 'accept joyfully the plundering of our property, since you know that you yourselves have a better possession and an abiding one" (Hebrews 10:34).
When we consider 'the prosperity gospel' in the light of the New Testament, it is revealed as a devilish and deceitful distraction to the people of God.
For Christians passing through Vanity Fair on his way to Celestial City, they are always tempted to stay and enjoy all the blessings of the world. Some have mistakenly thought that this was God's voice that beckoned to them, but it is not. Rather, may we, like John Bunyan's Christian, also 'set our eyes on the things that cannot be seen' (2 Cor 4:18) and aim at the 'pleasures which are in His right hand' (Psalm 16:11).
In His priceless Name,