Paul's standard greeting in his letters to churches, as well as individuals to whom he wrote, is, "Grace to you and peace from God the Father and the Lord Jesus Christ." There is no mention of the Holy Spirit.

This same greeting, with only minor variations, appears in every epistle that bears Paul's name: Romans 1:7; 1 Corinthians 1:3; 2 Corinthians 1:2; Galatians 1:3; Ephesians 1:2; Philippians 1:2; Colossians 1:2; 1 Thessalonians 1:1; 2 Thessalonians 1:2; 1 Timothy 1:2;2 Timothy 1:2; Titus 1:4; and Philemon 1:3.

The Holy Spirit is always left out of these greetings—an unbelievable oversight if the Holy Spirit were indeed a person coequal with God and Jesus Christ.

This is even more surprising when we consider that the churches to which Paul wrote had many gentile members from polytheistic backgrounds who had formerly worshiped numerous gods. Paul's epistles record no attempt on his part to explain the Trinity or Holy Spirit as a divine person equal with God the Father and Jesus Christ.

In Paul's writings, only in 2 Corinthians 13:14 is the Holy Spirit mentioned along with God the Father and Jesus Christ, and there only about our "fellowship of the Holy Spirit" (New International Version) with God and Christ (see 1 John 1:3).

The apostle Paul states clearly that "there is one God, the Father, of whom are all things...and one Lord Jesus Christ..." (1 Corinthians 8:6). He makes no mention of the Holy Spirit as a divine person.