Salvation by Grace & Ecumenical Inclusivism

Is everyone obligated to beliieve in the Gospel of Jesus Christ the first time they hear it?

I would say that depends. Anyone can say those things, but unless you have been convinced that they are true, you are simply giving lip service. God knows our hearts, and I don't think the insencerity of such a profession would mean anything, salvationally.

However, Romans 2:12-16 says that for those who are without the law, when they do what they law requires, they become a law unto themselves, because the law of God is written on their hearts. On the day of Judgement, God will reveal the secrets of our hearts and judge accordingly.

Matthew 25 lays out the criteria for that judgement. And it makes no mention of the ability to force yourself to believe in something of which you have not been convinced. It says that those who will hear the words "good and faithful servent" will be those who feed the hungry, clothe the naked, house the homeless, and take care of the sick.

James says the essence of true religion is to take care of the orphans and widows in their distress, and to remain unstained by the world.

The Roman Catholic Church put it this way in Lumen Gentium:

Nor is God far distant from those who in shadows and images seek the unknown God, for it is He who gives to all men life and breath and all things, and as Saviour wills that all men be saved. Those also can attain to salvation who through no fault of their own do not know the Gospel of Christ or His Church, yet sincerely seek God and moved by grace strive by their deeds to do His will as it is known to them through the dictates of conscience. Nor does Divine Providence deny the helps necessary for salvation to those who, without blame on their part, have not yet arrived at an explicit knowledge of God and with His grace strive to live a good life.

Lumen Gentium, 2nd Vatican Council, #16

The Parable of the talents tells us that from those who have been given much, much is required. Meaning that God judges us on what we do with what we have.

When Paul preached to the people of Athens, he made the staement that previously God had overlooked the age of Human ignorance, but was now calling all to repentence. So this begs the question, how was God able to overlook the age of human ignorance? In the same way he is able to overlook our sins today. Through the sacrifice of Jesus Christ on the cross.

Ephesians 2 tells us that salvation is a gift of God's grace for the reason of our faith, that it is not dependent on our works, lest we boast that we have earned our own salvation.

Romans 9 tells us that salvation is not dependent on human will or effort, but is by the Grace and Mercy of God, who has compassion on whoever he wishes.

God has bound himself by his promise to grant us salvation by his grace for the reason of our faith in Jesus Christ. In so doing, Jesus becomes the righteousnes for our unrighteousness. There is absolutely nothing preventing God from applying the substitute righteousness of Christ to anyone he wishes for any reason he wishes.

God has the ability to reveal himself to everyone in a manner that would make his existence incontrovertable. Yet, for reasons unknown to us, he chooses not to do so. If God were to hold this decision against those who have no rational basis with which to believe in his existence, how could he be called just?

1st John 4:7 & 16 says that God is love, that love comes from God, that all who love know God, that if they abide in love, they abide in God and God abides in them.

For those who have not been convinced of the existence of God, or the truth of the gospel of Christ, salvation is still possible provided they do what they know to be right. To love their neighbor as theirselves. This is the entire foundation of God's law.