John 14:6 Jesus said to him, “I am the Way, the Truth, and the Life. No one comes to the Father except through me.”
There are plenty of experts that offer to show people the path to true happiness. They come from every kind of background imaginable and some of these experts are older than Christianity. What is it that sets Christ apart? What makes His voice the one to listen to rather than, for example, the voice of Buddha? What does He have to offer that no one else can?
God created us. Before the world began, He designed us as an answer to prayers of the past, present, and future. Nothing about us is a mistake. Everything about us, from the parents who gave birth to us to the color of our hair, is a calculated part of the plan that God made for our lives. This plan is meant for our happiness and the happiness of those around us. God is the only one who knows that plan, so it makes sense that to find happiness we would need to turn to Him to find the right expert.
Now, there are plenty of religions out there who claim that following their practice will lead to happiness. When presented with so many choices, why choose Christ? The answer to that question is that there is only one God, only one religion, which professes a God who so loved His own creation and so desired their happiness that He literally became one of them. He allowed His infinite power, infinite knowledge, and limitless being to be placed inside the egg of a woman where He grew for 9 months just as every human being does. He humbled himself to become one of us, born in the usual human way, to grow from infant to child to adulthood just as we all do.
He did this for two reasons. The first reason is so that, by becoming one of us, He could show us by example how to find true happiness. Jesus wasn’t afraid to celebrate life. His very first public miracle was at a wedding feast, and later in Scripture there are those who criticize his disciples and him for doing too much feasting and drinking. He enjoyed life. He loved children. He had many people who loved to be around him because He brought joy and happiness wherever He went. He did all of this while owning no home, no transportation, without much of a bank account, having no formal education, and without any authority granted to Him by the state.
The second reason was so that He could bridge the gap between man and God, becoming truly one of us, and thereby restore to all men the path to Heaven. Heaven is the ultimate place of happiness, for in Heaven there is no sorrow and no suffering, no trials and no troubles, no worries of any kind. God loved us too much to allow the separation caused by sin to be permanent, and so He came to us and became one of us so that He could build a bridge strong enough and long enough to reach from Heaven to Earth.
This is why Jesus Christ, being 100% God and 100% man, is the only one who can show us the true path to happiness because He is that path. He is God made man, sent to reunite man with the God who created them and who loves them with reckless abandon. No other religion, no other expert, has or can do the same. That there are some religions where the Gods took on the form of men is true, but they did not become men, they did not die for the sake of their own creation, and they did not do so out of love for their own creation. Only in Christ do we find God reaching out to humanity to unite Himself with them and show them by example how to find true, lasting happiness by uniting themselves completely and totally to the very source of happiness.