Ephesians is perhaps the most spiritual letter that Paul wrote, and that indicates that the church in Ephesus at that time was in a very spiritual state. It was a very good church. There was nothing there for Paul to correct. Ephesians deals with living a heavenly life on earth. A church and a Christian can fulfil their function on earth only if they are heavenly-minded. The more heavenly-minded you are, the more you can fulfil God's purpose for you on earth. The more earthly-minded you are, the more useless you will be to fulfil God's purposes on earth, even if you say you are going to heaven when you die. Your home can fulfil its function for God only if it is a heavenly-minded home. The Lord's will for us is "that your days on earth may be like the days of heaven upon earth" (Deuteronomy 11:21 - KJV). This was not possible under the old covenant. But Ephesians tells us how we can live like that under the new covenant.
Ephesians 1:3 says, "Blessed be the God and Father of our Lord Jesus Christ Who has blessed us with every spiritual blessing in the heavenly places in Christ." Notice there that all these blessings are spiritual, not material. Earthly blessings were what the Israelites were promised under the old covenant. We can read that in Deuteronomy 28. This is what distinguishes the grace that Christ brought from the law that Moses brought. If there were a verse like this in the Old Testament, it would have read like this: "Blessed be God Almighty (not our Father) who has blessed us with every material blessing in earthly places in Moses." So those believers who are seeking primarily for physical healing and material blessings are really going back to the old covenant. Such "believers" are actually Israelites and not Christians. They are followers of Moses, not of Christ.
Does that mean that God does not bless believers materially today? He does - but in a different way. As they seek His kingdom and His righteousness first, all their earthly needs are provided for them. Under the old covenant, people sought only these earthly things and they got plenty of them - many children, much property, a lot of money, victory over enemies, honour and position on earth, etc. But under the new covenant, we seek for spiritual blessings - spiritual children, spiritual wealth, spiritual honour, spiritual victories (over Satan and the flesh, and not over the Philistines or human beings). Our earthly needs, like the health and money we need to do the will of God, are added to us. God will give us as much money as He knows will not ruin us. Under the old covenant, God may have made some people billionaires. But he doesn't do that for us today, because it might prevent us from seeking the things that are above - and thus destroy us.
The words "spiritual blessing" in Ephesians 1:3 could be translated as "blessing of the Holy Spirit". God has already given us every blessing of the Holy Spirit in Christ. We have only to claim them in Jesus' name. Imagine a beggar girl sitting begging by the roadside. A rich prince comes by and decides to marry her and puts millions of rupees into a bank account - an account from which she can draw money freely any time she wants. What a lucky girl she is! Once she had nothing but a little tin can with a few coins in it. But now she lives in grand style with the finest of clothes. She can withdraw any amount of money from the bank, because she has so many blank cheques signed by the prince. This is our picture, spiritually speaking. We can now go to the bank of heaven and claim every single blessing of the Holy Spirit because they are all ours in Christ's Name. Everything of heaven is ours in Christ if we remain in this bridal relationship with Him, if we can say, "Lord, I want to be true to You all my days on earth as Your bride." Then every blessing of the Holy Spirit is ours. We don't have to try and convince God that we deserve any of them - because we do not deserve any of them. Can you imagine that beggar girl imagining that she deserves all the wealth she got freely? Not at all. All that we receive is by God's mercy and grace. We can take everything of heaven because they have all been given to us freely in Christ. We cannot earn them by our fastings or our prayers. Many do not receive the blessings of the Holy Spirit because they try to earn them in these ways! We cannot receive them like that. We must accept them all through Christ's merit alone.