Therein lays the problem with Christian churches today. Nothing in the New Testament scriptures supports such nonsense. Jesus dealt with the sin problem over 2,000 years ago.
I agree that the only sin that blocks us from God is not accepting Jesus Christ as your personal Savior.
Mark 3:28-29 New International Version (NIV)
28 Truly I tell you, people can be forgiven all their sins and every slander they utter, 29 but whoever blasphemes against the Holy Spirit will never be forgiven; they are guilty of an eternal sin.”