That they may be Strong

In Ether 12:27, the Lord tells us that if we come unto Him, He will make our weak things strong. I have always loved this verse since I was little. It was applicable when I broke my leg, and I came unto Christ through prayer. I was able to feel strengthened physically and have my weak leg become strong. The Lord wants us to use our natural bodies to help and serve others. This is why He gave us the Word of Wisdom. He wants us to make our bodies healthy by eating healthy food and exercising. The Lord also wants us to stay in control of our bodies which is why He commands us not to drink alcohol, or do drugs or tobacco. If we follow the Word of Wisdom, the Lord can make our weak body become strong so we can serve Him.
The Lord also strengthens our spirit. When I am feeling down or overwhelmed, I can come unto Christ. Then, if I am humble and ask for things that I need to work on, the Lord will show me what I need to do to strengthen my testimony. He refines us, but He doesn't make us do it alone. The Lord is always with us helping us. He carries our burden with us and although we must still go through trials, we can do it relying on the Lord. 
"And if men come unto me I will show unto them their weakness. I give unto men weakness that they may be humble; and my grace is sufficient for all men that humble themselves before me; for if they humble themselves before me, and have faith in me, then will I make weak things become strong unto them." (Ether 12:27)