I. The Apostle shows in these verses on what grounds his knowledge rested his conviction of the Thessalonians' election the fact and mode of their being chosen for privilege and duty. He was fully persuaded of it, both on subjective and on objective grounds. The power and assurance with which he and his fellow-labourers preached in Thessalonica, on the one hand, and the eagerness and joyfulness with which the inhabitants of the city listened, on the other, these were to him evidences of divine grace working both in speaker and hearers, proofs of God's having marked them out above others for His favour and service. The presence and energy of the Holy Spirit were recognised by him. Such was his sacred enthusiasm, that he felt his own words to be far more than the mere utterance of one earnest human spirit struggling to impress others; to be indeed nothing less than the urgent words of the Spirit Himself, the Spirit of all truth, witnessing through him, in behalf of Christ and His salvation.
II. The other evidence adduced for Paul's knowledge of the election of the Thessalonian Church is their selection for privilege and duty. The first was subjective, the freedom, and fulness, and power in the Holy Ghost with which he felt he had preached to them. The other is objective, the eager, joyful readiness with which they had received his preaching. Their having been chosen of God is shown by their having themselves chosen God's Gospel as offered to them. "Much suffering," indeed, in itself proves nothing in regard to Christian character and attainment. But much suffering with joy in the Holy Ghost does. The believer knows that the via dolorosawhich he has to tread is a path of true joy when he recognises his Saviour's steps in it. Melanchthon used to write in his students' note-books "Kreutzesweg Lichtweg the path of the cross the path of light"; and it was a favourite saying of Luther's, "If Christ wore a crown of thorns, why should His followers experience only a crown of roses?" The stream of Christian life has two currents, distinct yet united, of tribulation and joy, ever wending its course, troubled and calm to the ocean of eternity beyond.
J. Hutchison, Lectures on Thessalonians,p. 25.
References: 1 Thessalonians 1:5. Spurgeon, Sermons,vol. xi., No. 648; E. White, Christian World Pulpit,vol. xviii., p. 344; Homilist,2nd series, vol. vii., p. 102.