The Holy Spirit refers to the third Person among God. The faith of this Trinity is the most fundamental and core faith. This truth can be all known and understood by believing in the gospel of the water and the Spirit. Why? The reasons are as follows.
1) Because sinners are creatures while God is the far-reaching One who created the vast universe and the entire mankind. Like this, the truth of Trinity cannot be known until one receives remission of all sins by believing in the gospel of the water and the Spirit.
2) Because of their transgressions, the hearts of human beings have been darkened by their sins. Just as nothing can be seen when a mirror is stained, the eyes of the hearts of sinners cannot see what the Triune God has done.
3) Without the enlightenment of the Holy Spirit, we cannot know the profundities of God’s heart. The Holy Spirit bears witness that the Word of God is the truth (John 16:13). Like this, the Holy Spirit enables us to know what the truth of the water and the Spirit is, for He is God Himself who is a complete Person with knowledge, emotion and will. He dwells in those who believe in the written Word of God and works with them. We must therefore worship Him, trust in Him, love Him, and obey Him.