Knowing, brethren beloved, your election of God. For our gospel came not unto you in word only, but also in power, and in the Holy Ghost, and in much assurance; as ye know what manner of men we were among you for your sake. – 1 Thess. 1:4-5.
When Paul wrote to these early believers in the gospel of the Lord Jesus Christ he makes a rather bold statement that he knew they were the elect of God. He gives two reasons he knew they were God's chosen people unto salvation.
1). The gospel came unto them through the ministry of the Word of God, "our gospel came not unto you in word only." Paul preached to them from the scriptures; "…As his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures, opening and alleging, that Christ must needs have suffered, and risen again from the dead; and that this Jesus, whom I preach unto you, is Christ" (Acts 17:3). He plainly set forth before them the glorious person and priestly work of the Lord Jesus. Some of them that heard the message believed to the salvation of their soul and some believed not (Acts 17:4-5). God has ordained the preaching of the gospel to the salvation of His people (1 Cor. 1:21; James 1:18; 1 Pet.1:23). Let us never discredit nor neglect these necessary means to the salvation of sinners. Paul said to those in Antioch in Pisidia, "It was necessary that the word of God should first have been spoken to you ( Acts 13:46). Our God when He effectually calls His people to Christ in faith, it is with the word of life (Eph. 1:13-14). If it was necessary in Paul's day, surely it is necessary in our day (2 Thes. 2:13-14).
2). The gospel also came in the power and revelation of the Holy Spirit. This is also necessary to the salvation of God's people, "also in power, and in the Holy Ghost, and in much assurance." We must not only hear the gospel, but it also must be made effectual to the heart of the sinner by the power and regenerating grace of the Spirit (1 Cor. 2:10). In the parable of the Sower the ground had to be prepared in order to bring forth fruit (Matt. 13:23). Our Lord told Nicodemus that he must be born of water (word) and the Spirit to enter into the kingdom of God (John 3:5). In Ezekiel's valley of dry bones there was the preaching of the word to the bones and the quickening work of the Holy Spirit giving life (Ezek. 37:4-5). Why preach to dead bones? God instructed Ezekiel to do so. Even so we are instructed to preach the gospel to spiritual dead sinners looking and expecting God to bless His word (2 Tim. 4:1). God has promised to communicate and give life, faith, repentance, regeneration and salvation through His ordained means (Isa. 55:11; Rom. 10:13-17).