If one keeps on sinning, he can reach a point of no return in the sense that he will not be able to overcome his sins anymore. On the other hand, one can reach for God in advance to prevent ever committing any serious sin. Best of all, seek union with the Lord right away no that sin no longer becomes an issue. Sin is real and deadly. Dwell in the Lord is the most effectively way to deal with it (or rather not to deal with it).