I think I'd rather build on a firm foundation of stone than on sand. Whether it's a home I'm building or my personal faith, I can't think of any situation where sand would make a good foundation and support for any lasting structure.
I hope that as I pass through the storms of life that I'll find my foundation truly has been built on the Rock of our Savior and not on the sands of worldly knowledge and human capabilities. I'm not sure we really know with certainty what our foundation is until we pass through severe storms. But I want to do everything possible to anchor myself to Him right now while the weather is decent and the rains only fall intermittently.
I've seen too many friends and others who profess to believe in Christ (and I think they really do believe IN Him...) but when severe storms hit, their homes are shaken, their foundations start to shift and crumble... and all too often the next time we see them they have been swept out to sea and are drowning.
They've maken the mistake of believing IN Christ (believing that He exists, is real, has done miracles and is God's son) but they don't believe that He really will fulfill His promises to support us during the storms of life. There's a disconnect between their belief in Him and their trust in Him.
Faith isn't real until it's been tried. And it's not true faith if the doubt prevails in the hard times.
I'm not saying that we should never doubt, or that we can just sing our way through the storms of life. I think that real faith comes through doubting, questioning and wondering... but then searching, praying, testing, and coming to a sure knowledge of Jesus Christ as our Savior. I also think that we have to shore up that faith on a daily basis through more than just talking, thinking, and wishing. We have to build faith through actions (such as praying, studying scriptures, attending church, serving others, etc.) in order to be able to withstand the storms.
We have to face some hard stuff and remain faithful throughout to be able to see that Christ has kept His promise and has carried us through it. That's the hardest part- to keep believing, hoping and doing while not seeing any immediate relief to what we're going through. That takes the kind of faith that's been built on a solid foundation. No shifting sands will ever give us the security that a solid rock can. We can't put our trust in and make a foundation of anything in this life except the rock of Jesus Christ. He is real and He is solid.
But it's up to us to build our house on the solid rock. Jesus won't force us to do the construction. He just provides the blueprints and the building site. We have to put in the labor and pay for the materials. But it's so worth it when the storms come up and we can sit in the safety of our dwelling, watching the storm rage from our secure vantage point and knowing that when it passes the sun will shine again and we will emerge safe and sound.