How should a Christian scripturally respond to someone who believes that a loving God would not send anyone to Hell but instead let everyone go to Heaven?
“Universalism holds that everyone will eventually go to Heaven—all will be saved in the end. Even though universalists appeal to biblical passages to support their view, this belief is in direct opposition to the teaching of the Bible. Let us examine the so-called ‘universalist passages.’
“Universalism originated in the Garden of Eden when Satan said ‘you will not surely die’ (Gen. 3:4). The appeal by Universalists to God’s desire to save all is unconvincing because the same God who reveals that He desires for everyone to be saved also reveals that not everyone is saved. Additionally, we must distinguish between God’s sovereign will (which God infallibly brings to pass in the world), and His permissive will (what He does not want in and of itself, but wills to occur in light of all of history considered together).
“Universalists often appeal to Romans 5:18 to support their position:
Consequently, just as the result of one trespass was condemnation for all men, so also the result of one act of righteousness was justification that brings life for all men.’ But in the next verse Paul says ‘For just as through the disobedience of the one man the many were made sinners, so also through the obedience of the one man the many will be made righteous.’ We cannot press Paul’s use of all in verse 18 any more than we can his use of many in verse 19, for if we do we make Paul contradict himself. Why take the all in opposition to the many, causing them to contradict each other?
“The word ‘all’ in the Bible is not always to be taken in the absolute sense—meaning every individual without exception. Mark 1:5 has ‘all’ of the people of Jerusalem going out to see John the Baptist. Obviously Mark doesn’t mean every single person in Jerusalem. The word all often means ‘all of some kinds’ or ‘some of all kinds.’ So when Paul says that Christ brought ‘justification that brings life for all men,’ he is making a reference to both Jews and Gentiles being saved—some of all kinds and not just the Jews, God’s first chosen people.
“Therefore we see that Paul’s point is that the effects of Adam’s sin and Christ’s righteousness reach ‘all men,’ meaning that the effects do not apply only to Jews, but extend to Jews and Gentiles alike. This is in accordance with what Paul has been saying since 1:5—that all men, Jew and Gentile alike, stand on equal level before God because of their sin, and all must come to God in the same way—through Jesus.
“Verses like 1 Corinthians 15:22, which say ‘As in Adam all die, in Christ all will be made alive,’ are also appealed to. But the all who are made alive in this passage (and others like it) is equivalent to all who belong to Christ, not all people without exception. This is because ‘In Christ all will be made alive’ qualifies the expression ‘each in his own turn: Christ, the first fruits; then, when he comes, those who belong to Him.’ This expression clearly defines who the all is that Paul is talking about—all ‘who belong to Christ.’ Paul is describing the manner through which death and life came—death through Adam and life through Christ. All who die, die in Adam. All who live, live in Christ. When we look further at the context, we also see that verses 1:18; 5:13; 6:9 are clear that everyone does not belong to Christ. Universalists do not acknowledge the Bible’s teaching as a whole, but attempt to argue from only a portion of the biblical data that has been taken out of context.
“Sometimes it is argued that the Bible’s promise that all things will be reconciled in Christ entails the salvation of all. This is not what the Bible means by the phrase. When the Bible talks of reconciliation of all things in Christ it means that the rebellion of God’s creatures against Him will be crushed and everything will finally be made to conform to the perfect plan of God. If we take the reconciliation of all things to mean the salvation of all things, then we must conclude that Paul taught that even the fallen angels would one day be saved. Furthermore, we would have to reject a significant body of data which says that there will be people in Hell for all eternity (Rev. 14:9-11; 20:15; Matt. 5:21-22, 27-30; 23:15, 33; 25:41, 46).”
(Above by Matt Perman, in Universalism Briefly Explained)
“Some could get the impression that Christians do not want everyone to go to Heaven. That is not true of Christians or of God. Ezekiel 18:32 God says, ‘For I take no pleasure in the death of anyone, declares the Sovereign LORD. Repent and live!’ Yes, we would like everyone to ‘choose life’ and live eternally joyfully serving God. However wanting something does not make it so. It is childish to think that what you want is always the way it is.
“God values our life, but above that He values us and our ability to choose.
“For whatever reasons, God chose to give us the ability and responsibility to chose whether to follow Him or not. God wishes us to follow Him, but for whatever reason, God chooses not to take away our choice to serve Him.
“To sum things up, truth is not created by our feeling about what we would prefer—fantasy is. The Bible teaches that God set up one way, through a relationship with Himself, to go to His Heaven. C.S. Lewis said in The Great Divorce, ‘Never fear, there are only two kinds of people: people who say to God, ‘Thy will be done’, and the other kind, whom God says to them, ‘thy will be done’.’ People can accept God’s way and go where the others who accept God’s way go. People can reject God’s way and go to the same place as the others who reject God’s way.”
(Above from http://www.biblequery.org/ )