Jesus also said "My kingdom is not of this world". If you miss that you totally misunderstand the gospel.
When the Lord told us to "seek first the kingdom of God and His righteousness" (Matt 6:33), that was in contradiction to seeking material gain. If we seek the kingdom, He promised that the basic things we need will be provided. If we seek material prosperity and forget the kingdom, we risk far more that loss of material benefit.
Not at all. Ther eis much tha is beyond material prosperity in this world, but that is clearly part of the Kingdom, and it is clearly God's intention that we should be abundant in this life as well as the afterlife, whatever form that takes.