And you also were included in Christ when you heard the word of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit. Ephesians 1:13
We are included in Christ when we hear and believe. This verse follows on from Paul’s teaching on predestination. We are included in God’s predetermined plans when we respond to Christ and receive him into our lives.
The verses regarding predestination are all plural. Paul explains that it’s the church that’s predestined. The church, Christ’s body, is ordained to be holy, blameless and adopted to sonship. So when we believe, we are included in Christ’s Body and become predestined.
Throughout the Old Testament we see that even though God chose the Jews to be his chosen people, he was always making a way for outsiders to be included. To such an extent we find Ruth the Moabite and Rahab from Jericho in Jesus’ genealogy (Matthew 1). Elsewhere we see God sending Jonah to Nineveh and other prophets to pagan lands. In John 10:16 Jesus says, “I have other sheep that are not of this sheep pen. I must bring them also…and there shall be one flock and one shepherd.” Jesus opened the way for Gentiles to be included in God’s family. Later, we find Peter struggling with this but eventually says, “I now realize how true it is that God does not show favoritism but accepts men from every nation who fear him and do what is right” (Acts 10:34-35).
God has made it possible for us all to be included in Christ when we hear and believe since it’s not his will that any should perish (2 Peter 3:9).