"How could God be Three and One at the same time? Simply because the Word of God distinctly affirms both truth. Both the Three and the One should be equally embraced without question.
The scriptural understanding. Firstly, a scriptural understanding of the Trinity is related to how God revealed Himself and made Himself known on the stage of history. The Father, Son, and Holy Spirit appear from Genesis to Revelation as a threefold unveiling of the one living God to fulfill his purpose with man. This is the economy of God in creation, redemption and sanctification. By this economy in the Scriptures we understand that God is triune.
Secondly, a scriptural understanding of the Trinity is also related to personal experience. Without experience there is no proper understanding of the Triune God. Paul makes this clear by speaking of the Trinity in the context of his actual experience. For example, Galatians 4:6, says, “And because ye are sons, God sent forth the Spirit of his Son into our hearts, crying, Abba, Father.” The Triune God is here revealed within the limits of Paul’s heart. Thus, the Father, Son, and Spirit must be experienced within our hearts in order to scripturally understand that He is triune.
The scriptural relationship. The scriptural revelation of the relationship between the Persons of the Trinity is found in two types of Scriptures. The first type is the verses that reveal that the Father, Son, and Spirit mutually indwell One another. One example is John 14:9b-10 where Jesus says: “…he that hath seen me hath seen the Father; how sayest thou, Show us the Father? Believest thou not that I am in the Father, and the Father in me? The words that I say unto you I speak not from myself: but the Father abiding in me doeth his works” (ASV). The relationship between the Father and the Son is one of mutual indwelling. That is, each Person interpenetrates and coinheres the Others. This mutual indwelling and interpenetration reveals the distinction within the Godhead of Father, Son, and Holy Spirit, and also preserves the fact that the Triune God is uniquely One.
The second type of Scripture showing the relationship between the Persons of the Trinity is the verses that specifically state that One Person of the Triune God is Another. Examples of this type are found in Isaiah 9:6 and 2 Corinthians 3:17. In one the Son is called the Everlasting Father and in the other the Lord (referring to Christ) is identified with the Spirit, viz., “Now the Lord is the Spirit.” These verses revealing the Persons being each Other must be understood with the verses revealing the Persons mutually indwelling each Other. That is, the understanding behind Isaiah’s utterance “the Son is called…the Everlasting Father” is Jesus’ utterance “…I am in the Father and the Father in me…” Both utterances are God’s Word and must be taken together. One utterance identifies the Persons, the other reveals the mutual indwelling of the Persons. By putting these two types of verses together, the Bible interprets itself.
From these Scriptures we can see that the oneness within the Godhead is of such a nature that the work of One Person is ascribed to the Other, and all Three function as One with One Name (Matt. 28:19) as One God (1 Cor. 8:4, 6).
Dr. Augustus Strong in his Systematic Theology, pages 330-334, fully discusses this scriptural relationship between the Persons of the Triune God. Speaking of the three Persons having one essence he says:
This oneness of essence explains the fact that, while Father, Son, and Holy Spirit, as respects their personality, are distinct subsistences, there is an intercommunion of persons and an immanence of one divine person in another which permits the peculiar work of one to be ascribed, with a single limitation, to either of the others, and the manifestation of one to be recognized in the manifestation of another. The limitation is simply this, that although the Son was sent by the Father, and the Spirit by the Father and the Son, it cannot be said vice versa that the Father is sent either by the Son, or by the Spirit. The Scripture representations of this intercommunion prevent us from conceiving of the distinctions called Father, Son, and Holy Spirit as involving separation between them…. This intercommunion also explains the designation of Christ as “the Spirit,” and of the Spirit as “the Spirit of Christ,” as in 1 Corinthians 15:45—“the last Adam became a life-giving Spirit”; 2 Corinthians 3:17—“Now the Lord is the Spirit”; Galatians 4:6—“sent forth the Spirit of his Son”; Philippians 1:19—“supply of the Spirit of Jesus Christ.”
The scriptural meaning. The scriptural meaning of the Trinity is for God to be experienced by man. All the verses related to the revelation of the Trinity are in the context of experience. When the Trinity becomes merely a dogma of theological debate, the scriptural meaning of the Triune God is lost.
God as triune desires that we experience Him by firstly being baptized “…into the name of the Father and of the Son and of the Holy Spirit” (Matt. 28:19); secondly, that we daily enjoy Him in our experience as Paul declared: “The grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit, be with you all” (2 Cor. 13:14).
This is the fourth of five articles in this Reply to the “Bible Answer Man”