All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Allaah Says (what means): {Verily! Those who believe and those who are Jews and Christians, and Sabians, whoever believes in Allaah and the Last Day and do righteous good deeds shall have their reward with their Lord, on them shall be no fear, nor shall they grieve.} [Quran 2: 62] The interpreters of the Quran interpreted the above verse to mean: "Those who believe: means in Mohammad the Jews, mean those who believed in Moosaa (Moses) and died as such before 'Eesaa (Jesus), Allaah exalt his mention, was sent as a Messenger, or that they saw him and believed in him. As regards the Sabians, it was said that they were a people who followed the previous Prophets, may Allaah exalt their mention. So Allaah will reward only those people, who believed in Allaah and the Last Day, and believed in the Prophet who was sent to them, and died while believing in all of this. However, after the Prophet Mohammad was sent, if one denies his message and did not believe in him, then he is a disbeliever and any other religion than Islam will not be accepted from him. Islam is the religion with which Allaah sent all His Prophets, may Allaah exalt their mention. Islam means submission and surrender to Allaah while believing in all His Prophets; Allaah Says (what means): {Indeed, the religion in the sight of Allaah is Islam.}[Quran 3:19] Allaah further Says (what means): {And whoever seeks a religion other than Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers.}[Quran 3:85] Another verse reads (what means): {He (Allaah) has ordained for you the same religion (Islamic Monotheism) which He ordained for Nooh (Noah), and that which We have revealed to you (O Mohammad ), and that which We ordained for Ibraheem (Abraham), Moosaa (Moses) and 'Eesaa (Jesus) saying you should establish religion (i.e, to do what it orders you to do practically) and make no divisions in it (religion) (i.e, various sects in religion).}[Quran 42:13]
Allaah also Says (what means): {And this (submission to Allaah, Islam) was enjoined by Ibraheem (Abraham) upon his sons and by Ya'qoob (Jacob), (saying), "O my sons! Allaah has chosen for you the (true) religion, then die not except in the Faith of Islam (as Muslims - Islamic Monotheism).}[Quran 2: 132] Moreover, the Prophet said: "I swear by Allaah in whose hand my soul is, no one hears about me, be he a Christian or a Jew, then dies not believing in what I was sent with, except that he will be among the people of Hell." [Muslim]
Therefore, there is no contradiction between the verse that is referred to in the question [Quran 2:62] and verse {Indeed, the religion in the sight of Allaah is Islam.}[Quran 3:19] The Christian scholars now have no excuse for not becoming Muslims and continue believing in the trinity. The trinity is an aberrant and clear disbelief, and High is Allaah from making this a belief of the Prophets, neither for 'Eesaa (Jesus), Allaah exalt his mention, nor for other Prophets, may Allaah exalt their mention.
Allaah Knows best.