Isaiah 46:4
"And even to your old age I am he; and even to hoar hairs will I carry you: I have made, and I will bear; even I will carry, and will deliver you."
There are two great differences between living a worldly life and living a Christian life. The world will use you until you are no longer useful and then they will cast you away. We are reminded of this in many of the people in the Scriptures. The world used Samson until they were done with him, and then they cast him away. The world used Judas Iscariot until they got out of him what they wanted, and then they cast him away. The world took from the Prodigal Son what they wanted, then when he had no more to offer they left him and he became a castaway.
On the other hand, when you serve God you will never become a castaway. The amazing thing about God is that when the world does not want you, God does. We are reminded in the verse above that you will never be a castaway with God. Let me remind you of four distinct times God uses us when the world casts us away.
First, you are never too old for God to use. In the verse above, God reminds you that He will carry you "to your old age." I look at the sports world and see athletes who only play into their thirties and then their career is over. I look at the world who rarely uses older people because they don't believe they have much to offer. Yet, it doesn't matter how old you are to God for He still wants to use you. You may be in your senior years of life, but you are not a castaway to God.
Second, you are never too young for God to use. Isaiah 49:5 says, "And now, saith the LORD that formed me from the womb to be his servant..." Study the Scriptures and you will find that God oftentimes uses youth. You don't have to wait until you are an adult for God to use you, but from a child you can be used of God. Don't waste valuable years of your life waiting on God to use you, for you are never too young to be used of God.
Third, you are never too bad for God use. Psalm 40:2 says, "He brought me up also out of an horrible pit, out of the miry clay, and set my feet upon a rock, and established my goings." Let me remind you that no matter how deep you have gone into sin, God still wants to use you. His hand will reach into the depths where sin has cast you and will bring you out and clean you up for His usefulness. You may think you are too bad for God, but you are never a castaway with God.
Fourth, you are never too ignorant for God use. We are reminded in 1 Corinthians 1:21, that God uses the "foolishness of preaching to save them that believe." You may think you are not smart enough for God use, but God will use anyone. God is not looking for your intellect, He is looking for a willing heart. God can take whatever intellect you have and use it for His glory if you will allow Him. Always remember that you are never a castaway with God.
Christian, be careful about thinking that God could never use you. It doesn't matter what you have done, you are not a castaway with God. Furthermore, be careful about placing anyone for any reason in the category of not being useful, for with God they are not a castaway and He can use them if they will yield to Him. Make it a priority in your life to remind people of their value to God and that he desires to use them.