“Remember therefore how thou hast received and heard, and hold fast, and repent. If therefore thou shalt not watch, I will come on thee as a thief, and thou shalt not know what hour I will come upon thee.” (Rev 3:3 KJV)
Jesus challenged the Church of Sardis to go back to their foundational doctrines and repent of not holding to that foundation. The Church had strayed from truth and died spiritually because they did not hold to the doctrines of the Apostles.
Jesus continually tells the Church to strengthen the foundation. A strong foundation in truth keeps us from wandering into false doctrine. It keeps us close to God and spiritual minded. We will think on the things of God and not allow the cares of this world to dominate our lives. A strong foundation will keep us spiritual and ready to meet God.
“Thy word have I hid in mine heart, that I might not sin against thee.” (Psa 119:11 KJV)