If God only let people into heaven who deserved to go there - then heaven would be empty! We all have sinned, and even one sin - just one - would be enough to keep you out of heaven.
In other words, someone who has followed Christ all their life doesn't deserve to go to heaven any more than this man who had been a Christian only a week. No one "deserves" heaven because we are all sinners. As the Bible says, "There is no one righteous, not even one ... for all have sinned and fall short of the glory of God" (Romans 3:10, 23). This is hard for us to accept, because down inside we all think God ought to reward us and allow us into heaven if we're good enough. But it isn't true, because God's standard is nothing less than perfection.
This is why we need Christ, for only He can save us. He was without sin - but on the cross, all our sins were placed on Him, and He died in our place. Now God in His grace offers us salvation - not as a reward, but as a free gift. The Bible says, "For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord" (Romans 6:23).
Don't let another day go by without Christ. No matter what you have done or how others may look at you, God loves you and wants to forgive and save you. And He will, if you ask Him to come into your life. Open your heart to Christ today.