Trinity Sunday is the first Sunday after Pentecost when we honour the Holy Trinity – the Father, Son and Holy Spirit. Although the word “trinity” does not appear in Scripture, it is taught in Matthew 28:18-20 and 2 Corinthians 13:14 (and many other biblical passages). On Trinity Sunday, the Christian Church ponders with joy and thanksgiving what the Father, Son and Holy Spirit have done to accomplish the salvation of sinful humanity. We remember the Father as our Creator, the Son as our Saviour and the Holy Spirit as our Comforter and Guide.
Charles Ryrie (1969); Balancing the Christian Life