The idea that all religions lead to God is logically untenable, since they directly contradict each other. In fact, the religions of the world do not even claim to serve the God of the Bible.
Regardless of what belief system that one espouses, he or she will inevitably be making a truth claim. Intolerance of opposing views is simply a consequence of being consistent with a worldview, and under various circumstances is necessary.
Christianity is unique among the world religions in that the message of salvation that it presents is by God's grace through faith (Ephesians 2:8-9). This is a stark contrast with man-made religions, for they believe salvation to be merited on the basis of human efforts. Christianity is the only religion which posits the realistic view of our sinful nature. The Judeo-Christian worldview is unique in that its God desires to have a personal relationship with mankind and is trinitarian.
The gospel is not reserved for an elite few who deserve salvation, but rather is available to all who call upon the name of the Lord. Nobody deserves to inherit the kingdom of God, since we have all sinned against Him. Christianity is inclusive in that the atonement of Jesus Christ is applied to all who believe on His name for salvation. Christianity is exclusive in that it presents Christ as the only way to obtaining fellowship with the Father.
If the religions of the world are valid, then it follows that Christianity is false (1 Corinthians 15:12-20). If there are multiple ways to salvation, then the gospel itself becomes redundant. Thus, we see that this pluralistic reasoning is actually a threat to undermine the Christian faith. No compromise or negotiation is permissible on this matter.
What objective good would a belief system hold if it taught that literally everybody was going to heaven, including those who have without a particle of remorse committed the most heinous of crimes? Would that really be a sound worldview to uphold in the first place?