Christians in different parts of the world would have different answers to your question, because they each face different kinds of opposition. In one country, for example, they may be persecuted by the followers of other religions, while in another place, they may face fierce opposition from secular people who are hostile to religion of any kind.
But behind all of these is an even greater hindrance–one that is universal. It is what the Bible calls "spiritual blindness"–our inner inability to see God's truth. The Bible says that "the god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ, who is the image of God" (2 Corinthians 4:4). Like fish you read about who've lived in dark caves for so long that they can no longer see, the human race has lived in sin for so long that we have lost the ability to "see" God's truth.
That is why we need Christ, for only His Spirit can open our spiritual "eyes" and help us "see" God's truth. And what do we "see" when that happens? Then we realize that God loves us so much that He sent His only Son into the world to save us. We realize too that Christ will forgive us if we only turn to Him.
Ask God to take away your spiritual blindness–and He will. Then turn to Christ and commit your life to Him. Others may not understand, but life's greatest joy comes from knowing Christ.