What sets Christianity apart from all the other religions in the world? This question can be best answered, according to Pastor Rick Warren, by asking another question.

"If you asked 50 random people, 'How do you get to Heaven?' you'd get a lot of different answers. But most of them would be based on the idea that you can (and have to) earn your way to Heaven," the pastor wrote on his website.

Some of the most common answers would be, "Try to be good, and do your best" or "Do more good things than bad things in life." For Warren, these answers were good, but the problem is they are based on a person's good deeds, not grace.

He cited the Bible verse Romans 3:24 which says, "All need to be made right with God by his grace, which is a free gift. They need to be made free from sin through Jesus Christ."

Warren explained that salvation is abslutely free, and all people need to do is accept it - you cannot earn it or buy it.

That alone is the "fundamental difference" between Christianity and every other religion, said Warren. "Every other belief system can be summarized by one word: 'do.' You do certain things to gain bliss, gain Heaven or some other kind of eternal reward, and gain God's approval," he added.

In contrast, people can summarize Christianity in just one word: "done." Warren explained that it is Jesus Christ who paid the ultimate price on the cross for people's salvation, but there are still many people who are hesitant to accept His gift of salvation.

"We all have people in our lives who do not have a relationship with Jesus. They may include family, friends, co-workers, neighbors, and acquaintances. The Bible says to pray for their salvation," he said. "Your prayers for people who do not know the hope we find in Christ do not go unheard. Keep on praying, and don't lose heart."

Sometimes God keeps quiet when people pray, but Warren said there are some secrets in securing an answered prayer. One of these is basing the request on God's character.

"Pray like you know God will answer you: 'I'm expecting you to answer this prayer because of who you are. You are a faithful God. You are a great God. You are a loving God. You are a wonderful God. You can handle this problem, God!'" said Warren.