"How do you know that Jesus is the only way to heaven? Have you studied or researched other religions and other belief systems?" When someone asked me that question, I had to honestly say I didn't. It was a fair question.
As a pastor and wanting to back up my claim with credibility, I set out to research and then teach on all the world religions and cults for a period of one year. From what I could surmise, I covered everything. I studied Christianity, Buddhism, Confucianism, Taoism, Mormonism, Catholicism, Bahai, Islam, and all the rest. I may have missed some, but all the major ones and even minor were covered.
After studying, teaching, and distilling all their major tenets, I came to this conclusion: Jesus is the only way to heaven. Hands down! "He is the only way to heaven! John, isn't that arrogant? How can you make such an absolute statement? There are no absolutes!"
When you take a second look at the statement, "There are no absolutes!", you clearly see it is a complete fallacy. The statement itself is an absolute statement. We all make absolute statements or believe in absolutes. "Popeyes makes the best chicken sandwich (It's true)! Trump is bad! Biden is a complete moron!" All of these statements, whether true or not, carry a level of absoluteness. Therefore, making the statement, "Jesus is the only way to heaven," is perfectly normal and okay in a world of absolutists.
What did I find that convinced me to make such a bold claim about Jesus? I found that Christianity as taught by Jesus in the Bible is the most just, logical, and loving in comparison to all the others. For instance, all of the cults and world religions fell into two categories when it came to their instructions on how to get into the afterlife or heaven. Christianity was the exception. You either had to believe and work your way to heaven without any assurance you gained access or the belief system did away with heaven, hell, and sin altogether. It was one or the other with all the world religions and cults.
For instance, Islam states you need to believe in Muhammed and Allah along with following the five pillars of Islam. However, all Muslims do not know if they will enter paradise because Allah could say no at the end despite following all the Islamic tenets on how to get to heaven. On another note, Hinduism completely does away with heaven, hell, evil, and sin. Just do good works and hopefully you will enter nirvana (nothingness/extinguishment) or be reincarnated into a higher caste system rather than a spider, worm, or some other lowly creature. There is no assurance.
Christianity, on the other hand, makes it very clear on how to enter heaven. The Bible states in Romans 10:9-10, "That if you confess with your mouth Jesus as Lord and believe in your heart that God raised him from the dead, you shall be saved. For with the heart man believes resulting in righteousness and with the mouth he confesses resulting in salvation." Furthermore, John 5:24 states, "I tell you the truth, 'Whoever hears my word and believes in Him who sent me has eternal life and will not be condemned. He has crossed over from death to life." Simply put, you need to believe in Jesus as Lord to be saved. What does this mean? You need to believe in him and follow his teachings. If you make a mistake or sin along the way, which everyone does, you just need to come back to him and ask for forgiveness and get back on the saddle of life again. It's a life of grace, forgiveness, and fairness. It's a life of real assurance.
You may ask the question, "How come it is so easy and straightforward? How come it is so generous?" Christianity deals with sin or evil in a just, complete, and loving way. God put all the sins of the world on his Son, Jesus, and sentenced him to death even though he was sinless. God lovingly paid for all our sins by sentencing his son to death. We just need to accept his gift by faith to receive complete absolution or cleansing from all our sin. We are thus forgiven and given new life through believing in Jesus. Christianity does not provide a cheap route to heaven, but a very costly one because it required the blood and death of God's son. You could say the crime of sin was justly paid for by the death penalty, the death of his son. Therefore, Jesus is the only way to heaven because he satisfies our need for justice and love in a very definite and clear way.
John 14:6, "Jesus said to Him, "I am the way, and the truth, and the life; no one comes the Father but through me."
Acts 4:12, "And there is salvation in no one else; for there is no other name under heaven that has been given among men by which we must be saved."
Titus 2:11-12, "For the grace of God has appeared bringing salvation to all men, instructing us to deny ungodliness and worldly desires and to live sensibly, righteously and godly in the present age."