"God has given us intellectual and moral power, but to a great extent everyone is the architect of his own character. Every day the structure more nearly approaches completion. The word of God warns us to take heed how we build, to see that our building is founded upon the eternal rock. The time is coming when our work will stand revealed just as it is. Now is the time for all to cultivate the powers that God has given them, that they may form characters for usefulness here and for a higher life hereafter. CT 222.2"
"According to the grace of God which is given unto me, as a wise masterbuilder, I have laid the foundation, and another buildeth thereon. But let every man take heed how he buildeth thereupon."
Both passages use the metaphor of building to describe character development and the importance of a solid foundation. 1 Corinthians 3:10 speaks of laying a foundation and taking heed how one builds, while the EGW passage emphasizes that everyone is the architect of their own character and should build upon the eternal rock.