What is this rich supply? In Ephesians 4:16 and Colossians 2:19 this supply is what flows out from the Head, Christ. In Philippians 1:19 it is the supply of the Spirit of Jesus Christ. In Galatians 3:5 the supply is the Spirit.
These verses show that the rich supply is the Triune God coming to us as all we need for our Christian life and for the building up of the Body of Christ. The Triune God comes to us as life, light, love, righteousness, joy, peace, meekness, humility, endurance, and more.
This rich supply causes our growth, which is the building up of the Body of Christ and of God’s house (see prior posts on Ephesians 2:19-22 and 4:15-16). In eternity there will be no further building work. The living Body of Christ and God’s living house will be mature and will become the living, eternal city, New Jerusalem.
In eternity everything will be complete and perfect. Nevertheless, there will still be the rich supply from the Triune God to maintain the freshness and vitality of the city. This rich supply of life is the Spirit, portrayed as the river of water of life, flowing out from the throne of God and of the Lamb (Revelation 22:1-2).
Photo of Ring Nebula by NASA & Hubble Heritage Team.