God promises we can have “ all the gold” we want. Malachi is prophesying to the people of Israel. He says just a few verses before that the people are robbing God. They are robbing him by not sharing with God the things that truly belong to him – those gifts and resources they have been charged to steward.
Malachi brings a challenge from the Lord: trust me and see what happens!
The Lord desires to grant us blessings and joy, meaning and hope. He desires to help us choose a true perspective, to grant us the opportunity to steward a meaningful life.
The “floodgates of Heaven” are not strictly physical currencies. They are spiritual ones. Which means that sometimes God grants us physical treasure, but He does so with spiritual intentions. Our physical gifts (money, ability, etc.) are spiritual resources. They are a means to an end, not an end in and of themselves. Which is much more valuable, much more true.
When the blessings of God come in, they transcend circumstances. They are riches of attitude and perspective, fruits of trust and of love, as well as riches of opportunity and resources. The riches of the Kingdom of God are transformative. A proper perspective can transform how we perceive the physical treasures God bestows upon us and how we use them.