Very True, Dear Friend
The Gospel doesn't say that a person who never knew Jesus will be rejected. Christ refers to those who disbelieve Him, such as the Pharisees - when He speaks in John 3, for example. In Romans 2, Paul says that ALL men, even the Gentiles, have a law written on their heart. The Catechism details the “natural law” pretty well.
Basically, God has written onto our hearts the Law of Love. Even a person who has never heard of Jesus Christ can “know” this law. If a person loves, He abides in Christ.
We know that we can do nothing good without Christ abiding within us. Thus, when a person who has never heard of Christ can listen to that divine natural law printed inside of us - and the Holy Spirit blows where He will. Thus, a person who has never heard of Jesus Christ CAN be saved - because they are not specifically rejecting Him - and they are following His Law of Love - which is the summary of the Commandments, says James.
The Catechism refers to the Muslims - some have not heard the truth of the Gospel, so they cannot reject it. They have been presented a scare crow by their mullahs, so they are considered invincibly ignorant (as the Catechism calls them and other such people). A person will not go to hell if he is invincibly ignorant and loves others.Some Muslims in countries like Iran and others don't know Jesus Christ and the Gospel. They haven't been presented it. So how can they reject it? They only reject a scare crow, much like some anti-Catholic friends who don't know Catholicism.
Those who love know God!
From the Catechism...
The Church and non-Christians
839 “Those who have not yet received the Gospel are related to the People of God in various ways.”325
The relationship of the Church with the Jewish People. When she delves into her own mystery, the Church, the People of God in the New Covenant, discovers her link with the Jewish People,326 “the first to hear the Word of God.”327 The Jewish faith, unlike other non-Christian religions, is already a response to God's revelation in the Old Covenant. To the Jews “belong the sonship, the glory, the covenants, the giving of the law, the worship, and the promises; to them belong the patriarchs, and of their race, according to the flesh, is the Christ”,328 “for the gifts and the call of God are irrevocable.”329
840 And when one considers the future, God's People of the Old Covenant and the new People of God tend towards similar goals: expectation of the coming (or the return) of the Messiah. But one awaits the return of the Messiah who died and rose from the dead and is recognized as Lord and Son of God; the other awaits the coming of a Messiah, whose features remain hidden till the end of time; and the latter waiting is accompanied by the drama of not knowing or of misunderstanding Christ Jesus.
841 The Church's relationship with the Muslims. “The plan of salvation also includes those who acknowledge the Creator, in the first place amongst whom are the Muslims; these profess to hold the faith of Abraham, and together with us they adore the one, merciful God, mankind's judge on the last day.”330
842 The Church's bond with non-Christian religions is in the first place the common origin and end of the human race:
“Outside the Church there is no salvation”
846 How are we to understand this affirmation, often repeated by the Church Fathers?335 Re-formulated positively, it means that all salvation comes from Christ the Head through the Church which is his Body:
Basing itself on Scripture and Tradition, the Council teaches that the Church, a pilgrim now on earth, is necessary for salvation: the one Christ is the mediator and the way of salvation; he is present to us in his body which is the Church. He himself explicitly asserted the necessity of faith and Baptism, and thereby affirmed at the same time the necessity of the Church which men enter through Baptism as through a door. Hence they could not be saved who, knowing that the Catholic Church was founded as necessary by God through Christ, would refuse either to enter it or to remain in it.336
847 This affirmation is not aimed at those who, through no fault of their own, do not know Christ and his Church:
Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart, and, moved by grace, try in their actions to do his will as they know it through the dictates of their conscience - those too may achieve eternal salvation.337
848 “Although in ways known to himself God can lead those who, through no fault of their own, are ignorant of the Gospel, to that faith without which it is impossible to please him, the Church still has the obligation and also the sacred right to evangelize all men.”338
325 LG 16.
326 Cf. NA 4.
327 Roman Missal, Good Friday 13:General Intercessions,VI.
328 Rom 9:4-5.
329 Rom 11:29.
330 LG 16; cf. NA 3.
331 NA 1.
332 LG 16; cf. NA 2; EN 53.
333 LG 16; cf. Rom 1:21, 25.
334 St. Augustine, Serm. 96,7,9:PL 38,588; St. Ambrose, De virg. 18 118:PL 16,297B; cf. already 1 Pet 3:20-21.
335 Cf. Cyprian, Ep. 73.21:PL 3,1169; De unit.:PL 4,509-536.
336 LG 14; cf. Mk 16:16; Jn 3:5.
337 LG 16; cf. DS 3866-3872.
338 AG 7; cf. Heb 11:6; 1 Cor 9:16.
Oops
I forgot to add the rest of #842 thru #845
All nations form but one community. This is so because all stem from the one stock which God created to people the entire earth, and also because all share a common destiny, namely God. His providence, evident goodness, and saving designs extend to all against the day when the elect are gathered together in the holy city. . .331
843 The Catholic Church recognizes in other religions that search, among shadows and images, for the God who is unknown yet near since he gives life and breath and all things and wants all men to be saved. Thus, the Church considers all goodness and truth found in these religions as “a preparation for the Gospel and given by him who enlightens all men that they may at length have life.”332
844 In their religious behavior, however, men also display the limits and errors that disfigure the image of God in them:
Very often, deceived by the Evil One, men have become vain in their reasonings, and have exchanged the truth of God for a lie, and served the creature rather than the Creator. Or else, living and dying in this world without God, they are exposed to ultimate despair.333
845 To reunite all his children, scattered and led astray by sin, the Father willed to call the whole of humanity together into his Son’s Church. The Church is the place where humanity must rediscover its unity and salvation. The Church is “the world reconciled.” She is that bark which “in the full sail of the Lord’s cross, by the breath of the Holy Spirit, navigates safely in this world.” According to another image dear to the Church Fathers, she is prefigured by Noah’s ark, which alone saves from the flood.334