A lot of issues arise from not clearly and properly defining the meaning of the Trinity. The Holy Trinity, as expressed in Scripture, is nothing more than the one and only Covenant God (I AM Who I AM) revealed in three co-equal and co-eternal distinct persons (members): the Father, the Son (Jesus the Christ), and the Holy Spirit.
This short writing is to speak against the “modalism” teaching and there not being distinction within the Godhead. According to this false doctrine, Jesus, the Holy Spirit, and the Father are simply modes (simultaneous manifestations) of one God, not distinct co-equal and co-eternal divine members of one Godhead. I will show 9 distinctions between the three, which then also affirms their co-equal divine mono-nature.
Distinction #1: Jesus says of the individuality of the Father, “My Father is greater than I” (Jn. 14:28 cf. Phil. 2:5-11).
Distinction #2: Jesus says to the Father of the individuality of Himself, “Glorify Your Son” (Jn. 17:1).
Distinction #3: Jesus quoted to the Pharisees David’s prophetic divine distinction and equality of the individuality of Himself and the Father (Matt. 22:41-46).
Distinction #4: Jesus said of the individuality of Himself and the Holy Spirit to the scribes and Pharisees that they will be forgiven if they blaspheme Him but not if they blaspheme the Holy Spirit (Matt. 12:31-33).
Distinction #5: Jesus speaks of the individuality of the Holy Spirit, Himself, and the Father (Jn. 14:25-26; 16:13-15).
Distinction #6: Jesus said if He bears witness of Himself by Himself His witness is not true. So Jesus says the Father and the Holy Spirit bear witness of Him—showing a distinction of the individuality of the Father, the Son, and the Holy Spirit (Jn. 5:31-37; 15:26; 8:14-18).
Distinction #7: Peter, in the first sermon recorded after Jesus, mentions the individuality of the Father, the Son, and the Holy Spirit (Acts 2:22-36).
Distinction #8: Paul speaks on the individuality of one Lord, one Spirit, and one Father of us all (Eph. 4:4-6 cf. Rom. 8:26-27, 1Cor. 15:15-28).
Just from these 9 alone we see this is not some doctrine picked up in later centuries as some suggest. Not to mention the book of Hebrews by itself displays—based on the Old Testament laws, the tabernacle, and such—the distinct persons of the Father, the Son, and the Holy Spirit! Jesus, David, Paul, Peter, and John are some good company to have if you’re going to hold to a doctrine!
The Holy Trinity, or the plurality of the Godhead, is apparent in Scripture (e.g. Gen. 1:26; 11:7, Isa. 6:8, Jn. 3:11; 17:11, 21) and supported in history—for it is recorded that the first century and second century believers also believed, accepted, and worshipped the Triune God (e.g. Justin Martyr AD150, Polycarp AD116 [disciple of the Apostle John], Irenaeus AD185 [disciple of Polycarp], and in the late 2nd century/early 3rd century AD, Tertullian).
The Apostles got it from Jesus, the early church got it from the Apostles, and we got it from the Scriptures passed on to us from the early church.
For those who may have questions about the heretical "Oneness/Modalism" doctrine, please check this site...Trinity versus Oneness.