The "prosperity" found through the cross is NOT worldly wealth. I would say the prosperity of the cross is defined in Colossians 1:19-20: "For in him all the fullness of God was pleased to dwell, and through him to reconcile to himself all things, whether on earth or in heaven, making peace by the blood of his cross."
Yes, pray for what you need. Yes, ask fellow believers to pray for you. But, no, don't get caught-up in prosperity gospel scams. But seek first the kingdom of God and his righteousness, and all these things will be added to you. (Matthew 6:33)