Purity of heart is often uncomfortable to think about. Sin can get in the way. But to ignore the truth of sin just because it's uncomfortable does not change the fact that it's true. The good news about sin is that it can all be forgiven by accepting Jesus Christ as Savior accomplished by the work of the cross of Christ. You can have changed and pure heart with God's help.
In a true Christian community, a person will both receive compassion and mercy from others and will be willing to respond to others who are in need with mercy. That does not mean that a loving Christ follower won't instruct you as to how you can change and walk closer to Christ. But, there will be love and compassion while doing it. Why? Because, 'apart from the grace of God there goes I' is always the attitude displayed by brothers and sisters who are followers of Christ. Let's practice this sort of mercy.
When someone really messes up their life, what is your response? Do you respond with, "Serves them right, they are getting what they deserve..." Think about Jesus' response to the woman caught in adultery. She had really messed things up, to the point where they were picking up stones to kill her. But, Jesus responded with, "Let him who has no sin pick up the first stone and hit her with it." It wasn't long before everyone fled, thinking about their own guilt, and Jesus mercifully forgave and sent her away with, "I do not accuse you. Go and sin no more."- John 8:1-11 Every single one of us need God's forgiveness like that. Thank Him today for His forgiveness of your sin.