Wherefore I give you to understand, that no man speaking by the Spirit of God calleth Jesus accursed: and that no man can say that Jesus is the Lord, but by the Holy Ghost.
Negative and positive tests of inspiration by the Spirit-the rejection or confession of Jesus' Lordship, not the possession of "tongues" (1 Corinthians 13:1; 1 John 4:2; 1 John 5:1). Paul gives a test of truth against the Gentiles; John against the false prophets.
By the Spirit - Greek, 'IN the Spirit,' that being the power and element in which he speaks (Matthew 16:17; John 15:26).
Of God ... Holy. The same Spirit is called at one time "the Spirit OF GOD," at another, "the HOLY Ghost," or 'Holy Spirit.' Infinite Holiness is almost synonymous with Godhead. The saying, 'Jesus is accursed' cannot emanate from "the Spirit of God," but from the evil Spirit. The saying, 'Jesus is Lord,' cannot emanate from man's natural spirit, but from "the Holy Ghost." 'Aleph (') A B C read the nominative, 'accursed Jesus!' and 'Lord Jesus!' Delta G read the Received Text.
Speaking ... say. 'Speak' implies utterance; "say" refers to that which is uttered. Here "say" means a continued spiritual and believing confession of Him.
Jesus - not merely the doctrine, but the historical "Jesus" (Romans 10:9) - that He is the Divine Lord incarnate.
Accursed - as the Jews and Gentiles treated Him (Galatians 3:13; cf. 'to curse Christ,' in Pliny's letter, Ep. 10: 97). Not the mere once-execration, but stedfast rejection. The spiritual man feels Him to be the Source of all blessings (Ephesians 1:3); that to be severed from Him is to be accursed (Romans 9:3).
Lord - acknowledging himself His servant (Isaiah 26:13). "Lord" is the Septuagint translation for the incommunicable name Yahweh (H3068).