The term Trinity was brought about in the second century to describe the Godhead.

1. Relationship. We are to know every aspect of the God we serve, especially in the nature of the Godhead. If there are indeed three persons existent within the God we serve, we must seek to know all three and not just one. Some know only one.
   1. John 17:3; 14:20, Philippians 3:10.
   2. We are to love, serve, and worship Him in all He is.
2. How many can systematically explain the doctrine of the Trinity?
   1. Most cannot.
   2. 2 Timothy 2:15.
   3. Jude 3.
   4. Most cults are much better equipped than those within the body of Christ. As Dr. Walter Martin once said, they can twist the average Christian into a doctrinal pretzel. We should commit to equipping ourselves to be able to defend our faith.
3. The unity or oneness of God.

   There's only one God (Deuteronomy 6:4, Isaiah 43:10, 44:6 & 45:22, 2 Samuel 7:22, 1 Timothy 2:5, 1 Corinthians 8:4).

   1. This is a compound rather than an absolute unity (Genesis 1:1, Deuteronomy 6:4).
   2. Examples of God speaking in the plural (Genesis 1:26, 3:22 & 11:7, Isaiah 6:8, Zechariah 12:10).
   3. Examples of compound unity in other things, composite rather than solitary unity.
      1. Genesis 2:24 & Mark 10:7-8. Adam didn't become Eve, but they became as one before God.
      2. Numbers 13:23-24. One cluster of grapes, from one stem, drawing their life from the same source.
      3. Genesis 11:6 & Acts 2:46. The United States could be said to rise as one to defend itself or to fulfill some purpose. A group could be said to stand as one in time of crisis.
4. There are three persons eternally existent in the one God. All are separate and distinct persons within the one God, yet each called God.
   1. God the Father (Galatians 1:1 & Philippians 2:11).
   2. God the Son (Isaiah 7:14, Matthew 1:23, Micah 5:2, John 1:1, 1:14, 1:18 & 8:56-59, Exodus 3:14, John 10:30-33, 14:8-9 & 20:19-29, Colossians 2:9, Philippians 2:5-11, 1 Timothy 3:16, Hebrews 1:3-8).
   3. God the Holy Spirit (Acts 5:3-4). He is both called God and has elements of personality.
      1. Intellect (1 Corinthians 2:11 & Romans 8:27).
      2. Will (1 Corinthians 2:11).
      3. Sensibility (Romans 8:26 & 15:30).
      4. He grieves (Ephesians 4:30).
      5. He speaks (Acts 13:2).
   4. The triune existence of God is confirmed in scripture. God is one in nature but three in person and manifestation.
5. Examples and illustrations of the Trinity.
   1. Scriptural illustrations of the Trinity.
      1. Birth of Jesus (Luke 1:35).
      2. Baptism of Jesus (Luke 3:21-22).
      3. Discourse of Jesus (John 14:2, 8-9, 15-18 & 15:26).
      4. Paul's letters (2 Corinthians 13:14).
      5. Creation (Genesis 1:1-2, Hebrews 1:2, Colossians 1:16-17).
      6. Resurrection (Jesus the Son - John 2:19 & 21, the Holy Spirit - Romans 8:11, the Father - Acts 3:26).
   2. Non-scriptural illustrations of the Trinity.
      1. Man.
      2. Water.
      3. Sun ray.
      4. Triangle.
      5. Mathematics.
      6. Universe.
      7. Government.
   3. Application: 2 Timothy 2:12, Galatians 1:6-9, 2 Corinthians 11:3-5, Jude 3, 2 John 9-11.