Of administrations - Margin, "Ministries." The word properly denotes "ministries;" so that there are different ranks and grades in the ministries which Christ has appointed, to wit, those specified in 1-Corinthians 12:9-10, 1-Corinthians 12:28.
But the same Lord - This refers evidently to the Lord Jesus, by whom these various orders of ministers were appointed, and under whose control they are; see the note at Acts 1:24; compare Ephesians 4:5. The term "Lord," when it stands by itself in the New Testament, usually refers to the Lord Jesus, the name by which he was commonly known by the disciples; see John 20:25. The fact also that this stands between the mention of the work of the Spirit 1-Corinthians 12:4 and the work of God 1-Corinthians 12:6, and the fact that to the Lord Jesus appertained the appointment of these various grades of officers in the church (compare Matthew 10:1 ff, and Luke 10:1 ff), is further proof that this refers to him. The design of the verse is, to show that all these offices had their appointment from him; and that since all were his appointment, and all were necessary, no one should be proud of an elevated station; no one should be depressed, or feel himself degraded, because he had been designated to a more humble office.

Differences of administrations - Διακονιων· Various offices in the Church, such as apostle, prophet, and teacher; under which were probably included bishop or presbyter, pastor, deacon, etc.; the qualifications for such offices, as well as the appointments themselves, coming immediately from the one Lord Jesus Christ.

And there are differences of administrations,.... Or ministries; offices in the church, ministered in by different persons, as apostles, prophets, pastors, or teachers and deacons; who were employed in planting and forming of churches, ordaining elders, preaching the word, administering ordinances, and taking care of the poor; for which different gifts were bestowed on them, they not all having the same office.
But the same Lord; meaning either Jesus Christ, whom the believer, by the Holy Ghost, says is Lord; who, as the ascended King of saints, and Lord and head of the church, appoints different offices and officers in it; and having received, gives gifts unto them, qualifying them for the same; all which comes through the same hand, and not another's; or rather the Lord, the Spirit, who calls men to these several ministrations, separates and fits them for them, and constitutes and installs them into them, and assists them in the discharge of them; since he only, and all along, is spoken of in the context as the efficient of these several things.

"Gifts" (1-Corinthians 12:4), "administrations" (the various functions and services performed by those having the gifts, compare 1-Corinthians 12:28), and "operations" (the actual effects resulting from both the former, through the universally operative power of the one Father who is "above all, through all, and in us all"), form an ascending climax [HENDERSON, Inspiration].
same Lord--whom the Spirit glorifies by these ministrations [BENGEL].

Administrations - Offices. But the same Lord appoints them all.