There are many "Health and Wealth" gospels being propagated today.  In fact, the number of religious works (in the worst sense of the term) who "through covetousness ... with feigned words make merchandise of [gullible, lust-driven individuals]" (2 Peter 2:3) is quite astounding.  However, God does, in fact, desire His people to prosper according to His will.  The apostle John expressed this as God led him by the Spirit to encourage us in his third letter thusly,

"Beloved, I wish above all things that thou prosper and be in health, even as thy soul prospereth."  3 John 2

But notice the condition for prospering in the Lord,  i.e., according to Lord's will: "even as thy soul prospereth."  God is not the "Santa Claus" personage many would like Him to be, a god who can be mocked and manipulated by feigned words and insincere vows to "deliver" the desires of the carnal heart on cue.  God is holy, righteous and just.  He responds according to His own purposes and according to what is best for His children.  When our will is in subjection to His, when our desires for truly centered on His glory, i.e., when our "soul" is truly prospering, we will prosper in all areas of our life according to that blessed will, i.e., according as He deems best for us.  To the saint who truly loves the Lord with his whole heart, this is a blessed promise, a condition that is "not grievous" (1 John 5:3). 

We understand that our own children often do not know what is best for them.  As parents, we accept their requests in love, but with the understanding that we will do only what we "know" will be best for them.  God is infinitely more knowledgable and loving than we.  He understands our needs before we even ask him (Matthew 6:8).  Because He is an infinitely wise and loving Father, He does not blindly accept our petitions and act on them.  Rather, because He knows that our infirmities often prevent us from knowing what is truly best for us and glory for Him, He provides His own Spirit to help our infirmities "for we know not what we should pray for as we ought: but the Spirit maketh intercession for us with groanings which cannot be uttered.  And he that searcheth the hearts knoweth what is the mind of the Spirit, because he maketh intercession for the saints according to the will of God" (Romans 8:26b, 27).

This brings me to my point: it is the Lord's will that we prosper, but being the holy God that He is, he can only prosper us as we walk according to the truth.  It should go without saying that "[His] word is truth" (John 17:17b).  Bottomline: we will prosper as we willingly do as the Lord has commanded us.

The book of Joshua states this truth very plainly:

"This book of the law shall not depart out of thy mouth; but thou shalt meditate therein day and night, that thou mayest observe to do according to all that is written therein: for then shalt thou make thy way prosperous, and then thou shalt have good success."  Joshua 1:8

Would you be a success and enjoy eternal blessings?   Then do what the Lord's Word instructs you to do; do all that His Spirit is pressing you to do right now. Would you prosper, then "seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you" (Matthew 6:33).

The way to true blessing is very plain.  Don't let your own fleshly lusts or the many religious charlatans of these last days confuse you.  God's Way is the truly blessed way.  Obedience to His way brings peace, joy and both temporal and eternal blessings.  Don't be deceived and, thereby, turn aside from resting in the "simplicity that is in Christ" (2 Corinthians 11:3): God's will blesses; Selfwill does not.