God said that He would not hold any good thing from you if you will simply do what He said.
Read it for yourself. “Ps 84:11 For the LORD God is a sun and shield: the LORD will give grace and glory: no good thing will he withhold from them that walk uprightly.” Who is the author? Almighty God. He doesn’t change and He is not a respecter of persons. He is our Creator and He is all powerful. Did He lie? Absolutely not. Then why don’t I have it?
First of all He said it is reserved for them who walk uprightly. That is not “uprightly” according to my opinion nor yours. It is according to God’s standard. As you study the Word of God you will come face to face with what God says is walking uprightly. It means to conform to what He says to you, about you and for you. Searching it out is your responsibility. God will not force you to read it or to heed it. The choice is yours.
There is another consideration to be dealt with in receiving what God desires for you. If you are walking uprightly according to His Word, God said He would not withhold any good thing from you. However, there is a devil on the loose who will do all he can to keep you from receiving any good thing from God. He will mess with you any way he can. He will cause you to doubt and will steal your faith if he can. He hates you and wants to rob, steal, confuse, strike fear and kill you including your faith, testimony, peace of mind and relationship with God. He has had a lot of practice and has been all too successful in the Christian community.
One more thing. What you consider is a good thing for you might not be what God sees as being good for you. You might think: a million dollar mansion would be great. It would be a good thing. Would it? If God gave it to you, could you pay the insurance, upkeep, electric bill and heat bill? Possibly you could get a job to cover the expenses as you see them but then it might require you to miss church, keep you from doing the will of God for you and replace your peace of mind with worry and the cares of this world. God knows best what is the best thing for you and He only wants to do you good whereas the devil only wants to do you evil. Who will win?