During the Savior's ministry, He made it clear that His purpose was to minister to the house of Israel. To the woman of Canaan he said, I am not sent but unto the lost sheep of the house of Israel (Matt 15:24). When he sent out the Twelve as missionaries, he counseled them, Go not into the way of the Gentiles, and into any city of the Samaritans enter ye not: But go rather to the lost sheep of the house of Israel (Matt 10:5-6). Prior to the resurrection, the message of the gospel was to be sent exclusively to the house of Israel. They were to be the first to hear the gospel in order to fulfill the word of the Lord when he said, the first shall be last, and the last shall be first (Matt 19:30). After He was resurrected, the Savior would not appear to any who were unbelievers and unworthy to witness the resurrected Lord. Therefore, the Gentiles never received His personal ministrations nor did they hear his voice. But the day will come when the last shall be first.
James E. Talmage
"Even the Jewish apostles had wrongly supposed that those 'other sheep' were the Gentile nations, not realizing that the carrying of the gospel to the Gentiles was part of their particular mission, and oblivious to the fact that never would Christ manifest Himself in person to those who were not of the house of Israel. Through the promptings of the Holy Ghost and under the ministrations of men commissioned and sent would the Gentiles hear the word of God; but to the personal manifestation of the Messiah they were ineligible. Great, however, will be the Lord's mercies and blessings to the Gentiles who accept the truth, for unto them the Holy Ghost shall bear witness of the Father and of the Son; and all of them who comply with the laws and ordinances of the gospel shall be numbered in the house of Israel. Their conversion and enfoldment with the Lord's own will be as individuals, and not as nations, tribes, or peoples." (Jesus the Christ, p. 728-9)