The phrase "outward expression" means showing or revealing one's thoughts, emotions, or ideas through behavior, actions, or physical appearance for others to see or understand. Full definition
It encourages students to reflect on the idea of «outward expressions of inward grace» through a range of activities. (tes.com)
Many outward expressions are suitable, the appropriate one in any given case depending on personality type and on the person's social and cultural situation. (religion-online.org)
Nothing can replace the love of a mother in the maturing of a child, especially in the maturing of the Christ child, but that mutual love can find outward expression in the environment of the family represented primarily by the father. (faith.org.uk)