Acts 10:34-35 ... "And Peter said, 'I most certainly understand now that God is not one to show partiality, but in every nation the man who fears Him and does what is right, is welcome to Him."
The tenth chapter of Acts describes a great turning point in the history of Christianity and the progress of the church. Although Jesus had commanded that "repentance for the forgiveness of sins should be proclaimed in His name to all the nations, beginning from Jerusalem," (Lk. 24:47), His disciples had not surpassed the bounds of Judaism before this chapter. Apparently these people, who had been reared to believe that Gentiles were the off-scouring of the earth, could not conceive that the Kingdom of God was also open to those of any nation who would be happy to meet its requirements for citizenship. Even the apostles did not have this vision. So when God willed to convert Cornelius, a Roman army officer, He found it necessary to convince Peter by means of a vision (vs. 9-15) that Gentiles were eligible for discipleship in Christ and membership in His church.
When Peter came to the house of Cornelius in Caesarea, he used the "keys of the kingdom" given him by Jesus in Mat. 16:19 to open the way for the first non-Jew to enter as a child into God's family, He was speaking to himself as much as to others when he said, "God is not one to show partiality." All his life he had been taught as a Jew the opposite, that God's covenant-love rested upon those who were descended from Father Abraham. Some fifteen years later Peter used this revelation to try to convince certain Jewish brethren that Gentiles did not have to be proselytes to Judaism before they could become Christians. In Acts 15:7,9 he told them, "Brethren, you know that in the early days God made a choice among you, that by my mouth the Gentiles should hear the word of the gospel and believe. ... And he made no distinction between us and them, cleansing their hearts by faith." The door to the church was not at the end of the corridor of Jewish observance; it opened straight from the world of Gentile abominations.
Nevertheless, one has to leave those abominations behind in that sordid world when he enters into the Kingdom of God. These days we are not much concerned about Jewish prerequisites to Christian discipleship, but the principle of what one must do to enter into that discipleship is certainly a matter of paramount concern. In order to be accepted by God and granted citizenship in His Kingdom, one must "fear God and do what is right." To fear God means to hold Him in the most profound respect possible. In fact, it is a spirit that transcends respect and attains to reverence. God must be recognized as present at all times and in every place, (Psa. 139:7-12). As one humbles himself in the immediate presence of royalty, the God-fearer will continually humble himself in the perceived presence of Him who is King of kings and Lord of lords. To "do what is right" (also called "righteousness") means to observe the canon of behavior God has set forth in His book of instruction, the Bible. Presentations designed to convince others of one's righteousness are no substitute for the real thing, obedience to the word of God. Jesus declared in Mat. 7:21, "Not every one who says to Me, 'Lord, Lord,' will enter the kingdom of heaven, but he who does the will of My Father who is in heaven." Anyone who is irreverent, or who balks at obedience to God's will, is denied entrance into the Kingdom of God.
All who submit themselves to these requirements shall indeed be accepted. This is emphasized in Gal. 3:26,28 as follows, "You are all sons of God through faith in Christ Jesus. ... There is neither Jew nor Greek, there is neither slave nor freeman, there is neither male nor female, for you are all one in Christ Jesus."