The Holy Spirit

The Holy Spirit, proceeding from the Father and the Son, is of one substance, majesty, and glory with the Father and the Son — very and eternal God.

When the Counselor has come, whom I will send to you from the Father, the Spirit of truth, who proceeds from the Father, he will testify about me.
— John 15:26 (WEB)

Note

Wesley followed the Western filioque — that the Spirit proceeds from the Father AND the Son.

Bible references

John 14:16-17,26 · John 15:26 · John 16:7-15 · Acts 5:3-4 · Romans 8:9-11 · 2 Corinthians 13:14