I do believe that only a minority of people on the earth will be saved. Christ could have died for everybody although only a small percentage of people will accept Him.
13 “Enter by the narrow gate. For the gate is wide and the way is easy that leads to destruction, and those who enter by it are many. 14 For the gate is narrow and the way is hard that leads to life, and those who find it are few. Matthew 7:13-14 ESV
In my understanding of the scriptures, with the determination to make them harmonize, is that there will be many more that go to heaven, than there are that go to hell. If you will bear with me, I will explain why I think that.
Spiritual Israel, which is made up of every kindred, and tongue, and people, and nation (Rev 5:9) Spiritual Israel is Jacob, whom God has changed his name to be no more called Jacob, but to be called Israel.(Gen 32:28).(Rom 9:6-13)
Most of spiritual Israel turned away from God and began to worship idols, they were still God's people, just disobedient children, but God left in the midst of them a remnant that shall trust in the Lord. (Zeph 3:11-13)
So there are two types of God's children, Those that are disobedient, who are going about teaching false doctrines, and the remnant that trusts in the Lord.
There is a wide gate which are God's children who are disobedient and preaching false doctrines, and there is a strait gate which are the remnant of spiritual Israel that trust in the Lord, which leads them to enjoy an abundant and peaceful life as they sojourn here on earth.
I believe the scriptures to teach that God's children are The church, and there is visible church, which is the remnant, and there is an invisible church which is the wide gate.
Ezk 10 speaks of a wheel within a wheel that harmonizes with the two gates. The Larger outer wheel being the wide gate and the inner smaller wheel being the strait gate.
These scriptures seems, to me, harmonize with each other. When Jesus was on earth preaching the gospel, their were far more people who rejected Christ's doctrine (disobedient children) than there were who accepted it