"Inward grace" means having a positive and good quality or virtue within oneself. It refers to the inner qualities that make a person good or moral, such as kindness, compassion, or forgiveness. Full definition
It encourages students to reflect on the idea of «outward expressions of inward grace» through a range of activities. (tes.com)
, or that it will make God happy (Jesus did it fulfill all righteousness), or that it is necessary to get baptized to receive eternal life (for what other reason would you do it, you can't find outward sign of inward grace in the NT, that is just a modern tradition). (redeeminggod.com)
Probably the most familiar description is that of St. Thomas, who borrows St. Augustine's idea that sacraments are outward signs instituted by Christ causing inward grace. (religion-online.org)