Grace, justification and holiness
Grace is God’s free gift, not something earned by independent human achievement. Justification forgives sin and brings a person into renewed life in Christ. Human cooperation is itself enabled by grace; it is neither irrelevant nor a competing source of salvation. The call to holiness reaches every Christian vocation and is lived through charity rather than a claim to spiritual superiority.
Follow the sources
An original library introduction, with sources for further study. This is a starting point rather than a complete treatment or a finished formation lesson.