Luke 18:17 (NKJV)
Assuredly, I say to you, whoever does not receive the kingdom of God as a little child will by no means enter it."
The gospel of Jesus Christ is not complicated. As a matter of fact, if we make it complicated, we cause people to stumble. A child is simple and humble and without fear. That is the way God wants us to approach him with no ideas of merit or status. A child is full of eagerness and expectancy and how that is demonstrated when a person truly gives their whole heart to Jesus Christ.
Here it is, the simple gospel: The Bible says we are all sinful and cannot be with God because He is too holy to allow sin in heaven. But the Bible says that Christ died in our place to take away our sins. He came back to life on the third day just as he said he would. He offers forgiveness of sins as a gift to us that he has paid for by his death on the cross. To be saved from our sin and the consequences, we simply accept his gift to us by believing. Then we begin to let him tell us what to do as we thankfully obey him.