St Thomas also know as Doubting Thomas was one of Jesus’s 12 disciples and was one of the last disciples to believe that Jesus had risen from the dead, thus getting the nickname Doubting Thomas. The reason he is the patron of architects is because before he was a Disciple he was believed to be an Architect for the king of the Indies.
St Thomas Prayer
Come, Holy Spirit, Divine Creator, true source of light and fountain of wisdom! Pour forth your brilliance upon my dense intellect, dissipate the darkness which covers me, that of sin and of ignorance. Grant me a penetrating mind to understand, a retentive memory, method and ease in learning, the lucidity to comprehend, and abundant grace in expressing myself. Guide the beginning of my work, direct its progress, and bring it to successful completion. This I ask through Jesus Christ, true God and true man, living and reigning with You and the Father, forever and ever.