The Apostle Paul
Ephesians 1:3ESV·traditional attribution

Blessed be the God and Father of our Lord Jesus Christ, who has blessed us in Christ with every spiritual blessing in the heavenly places,

John Calvin Reformed @genevareformer

3. Blessed “As to the accumulation of cognate terms in εὐλογητὸς εὐλογήσας and εὐλογία, it may be observed, that in composition such was by the ancients, especially the early writers, rather sought after as a beauty than avoided as a blemish.” — Bloomfield. be the God and Father of our Lord Jesus Christ.

Matthew Henry Presbyterian @wholebiblehenry

He begins with thanksgivings and praise, and enlarges with a great deal of fluency and copiousness of affection upon the exceedingly great and precious benefits which we enjoy by Jesus Christ. For the great privileges of our religion are very aptly recounted and enlarged upon in our praises to God. I.

Commenting on Ephesians 1:3-14

Albert Barnes Presbyterian @notesbybarnes

Verse 3. Blessed by the God and Father of our Lord Jesus Christ. This commences a sentence which continues to the close of Verse 12. The length of the periods in the writings of Paul, is one cause of the obscurity of his style, and renders an explanation often difficult. The meaning of this phrase is, that God has laid a foundation for gratitude for what he has done.