A woman named Lydia, from the city of Thyatira, a seller of purple fabrics, a worshiper of God, was listening; and the Lord opened her heart to respond to the things spoken by Paul. 15 And when she and her household had been baptized, she urged us, saying, “If you have judged me to be faithful to the Lord, come into my house and stay.” And she prevailed upon us. (Acts16:14-15)
The above passage is often headed “The First Convert in Europe”, Thyatira having become a part of that continent. In terms of Lydia, one notes that having had her heart opened to respond to the Gospel she and her household were immediately baptized – typical of the conversions we read about in Acts.
This event is likely to have occurred in the early 50s AD, but what about the rest of Europe? The subject can be examined HERE in an article from Encyclopedia.com. Christianity in parts of Western Europe, for example the British Isles, did not become established until the third or fourth century (Wiki article HERE). Legends of mid-first century Christian communities becoming established as a result of missions undertaken by St Philip or Joseph of Arimathea have been widely discredited. The first archaeological evidence and credible records showing a community large enough to maintain churches and bishops dates to the 3rd and 4th centuries. Up to that point the vast majority if not all of these communities within Britain will have been in ignorant of the Gospel.
With that in mind I would ask Christian readers to ponder anew: do they really believe that God would leave such vast swathes of people in ignorance for generations if the eternal wellbeing of their soul depended on it? As I am in the business of demonstrating, thanks to a role for natural law (which many of the earliest Fathers articulated but Augustine and later Western theology came to regard as heresy) such is not the case. God and the Man He has appointed to judge every soul are NOT cosmic Monsters with a rationale entirely incomprehensible to human reason. Christ as the incarnate Word through Whom and for Whom all things were created has ensured that every person entering the world possess the faculties by which the soul may ultimately be accepted into God’s eternal kingdom. Conscience and compassion are the keys, for everyone who responds positively to the former and implements the latter (however feebly) is judged to have served Christ Himself (Mt25:40). In Paul’s language, works of the Law such as circumcision do not make a man righteous in God’s sight but faith that works through love (Gal5:5-6).
Love and faith are inseparable: faith is the agent of love and love is the product of an underlying faith. That is why the sheep and goat passage in Matthew 25 referenced above is NOT advocating justification by works. It is why the “sheep” were justified regardless of the quality or quantity of their acts of kindness – they just had demonstrated they had possessed the quality (agape – compassionate love) that can only be derived from an underlying faith – a faith in the innate Light and Law of Christ to which the conscience itself bears witness (cf. Jn1:9; Mt18:6; Rom2:15; 1Jn4:7-8)
Christianity pertains to the provision of spiritual resources by which the incarnate soul can be saved from the ravages of what Paul describes as “the body of this death”. He is referring to the procreated intellectual vessel we inherit from our parents, ultimately from fallen Adam whose instincts are at loggerheads with those of the God-given spirit (Rom7:22-25). Whilst all who possess what 2nd century Clement of Alexandra described as a common faith  have been reconciled to God through Christ’s death, the Christian is also being saved (soul-healed) by participation with Christ’s life (Rom5:10).
For whilst our Heavenly Father is kindly disposed to all who respond positively (i.e. faithfully) to the natural precepts He has instilled within them, He does not wish us all to marry His Son. That requires something of a transformation that must commence whilst still in mortal flesh: for “those He did foreknow, He predestined to become conformed to the image of His Son” (Rom8:29). And in the context of the subject of this post, God will have ensured that those who are the elect of God and Christ’s eternal Bride will have lived and resided within the timeframe and location to respond to the Gospel.
Yet that does not mean that the rest have been hard done by, for those who do become the disciples of Christ embark upon an arduous route: the way of the Cross. They must be willing to set aside everything they hold dear including life itself in order to gain Christ for now and eternity. That is why Christ likened responding to the call of the Gospel as like someone intending to build a tower or a king about to go to war. It can never be a mere state of mind – “firmly believing in God’s promise of mercy to sinners” or “being assured in one’s heart that Jesus died for me as Saviour”, or “looking to the finished work of Christ and applying it to myself”. Such is the understanding of many but It is far removed not only from the teaching of Christ but from the perspective of the Apostle Paul: “Brethren, I do not regard myself as having achieved it as yet; but one thing I do: forgetting what lies behind and reaching forward to what lies ahead, I press on toward the goal for the prize of the high calling of God in Christ Jesus” (Phil3:13-14).
Such is the theology of glory espoused by the earliest Christian writers, challenged by Augustine and rejected absolutely by the Protestant Reformers. Yet the Cross of Christ remains at the Gospel’s heart. It is the fruit of Christ Passion, especially the sacramental blessings of His Body and Blood that enable the proportional few who partake of them to obtain the hope of glory (Col1:27). It is the grounds upon which many more with the common faith we have been describing are pardoned and finally accepted into God’s Kingdom.
All is explained in detail and integrated with the rest of Scripture in The Little Book of Providence  , a summary of the main points being provided in my 95 theses.
 Clement of Alexandria (A.D.153-217) The Stromata Book V chap. 1
 Free PDF HERE