Fundamental evidence that the Holy Spirit would, after Jesus' return to His Father, reveal new things, and thus disclose that which had been previously hidden can be found in John 16: 12-14: "I still have many things to say to you, but you cannot bear them now. However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come. He will glorify Me, for He will take of what is mine and declare it to you." With these words, Jesus Christ promised His Apostles that they would receive further explanations about God's nature and plan of salvation through the Holy Spirit.
The early Apostles experienced the activity of the Holy Spirit in the manner that the Lord had announced to them. The letters of the Apostles bear witness to the fact that the Holy Spirit had opened up to them an extensive understanding about the Lord (Philippians 2: 6-11; Colossians 1: 15-20) and of future events (1 Corinthians 15: 51-57). Their activity and testimony was permeated by that which the Holy Spirit revealed to them (Ephesians 3: 1-7).
The preaching of the Apostles of Jesus active today is based on the statements of Holy Scripture (see 1.2.5). They are guided by the Holy Spirit in their teaching commission. It is in this manner that the aforementioned promise of the Son of God is also fulfilled today: the Holy Spirit keeps alive the self-revelation of God manifested in Jesus Christ, brings it to life in the present, and points to the appearing of the returning Christ. The incarnation, death, resurrection, and return of the Son of God are at the centre of this revelation today.
Beyond that, the Holy Spirit imparts to the apostolate new insights about God's activity and plan of salvation, which, although intimated in Holy Scripture, have not yet been fully revealed. An important example that bears mentioning is the teaching that salvation can also be attained by the departed (see 9.6.3).
On the basis of his teaching authority, it is incumbent on the Chief Apostle to proclaim such revelations of the Holy Spirit, and to declare them as binding doctrine of the New Apostolic Church.
Jesus Christ promised His Apostles that they would receive further clarification about the nature of God and the plan of salvation through the Holy Spirit. (1.3)
The Holy Spirit grants the apostolate new insights concerning God's activity and plan of salvation, which are already intimated in Holy Scripture. (1.3)