For no one can lay a foundation other than that which is laid, which is Jesus Christ. Now if anyone builds on the foundation with gold, silver, precious stones, wood, hay, straw, each one’s work will become manifest, for the Day will disclose it, because it will be revealed by fire, and the fire will test what sort of work each one has done. (1 Corinthians 3:11-13 ESV)
Paul is talking about our work as servants in expanding the Kingdom. We build foundations in people (planting seed, watering it). It is important that we build the right foundation in them – Jesus Christ. Believers need to have a solid foundation, which is only Jesus because when we are tested with life’s trials and “going through the fire” our foundation is laid bare.
What will our foundation be when revealed? Will it be something other than Jesus or will we be clinging to Him as our foundation and salvation? Like Job, when all other things are stripped away, will we continue to love Him despite the circumstances?
That is when our foundation is God.