God is giving you the opportunity to be used directly by Him to actually save someone's life. Even if you can only spare two hours a month, God can make your time fruitful. If God is calling you to one of these ministries, take a step of faith and follow God's call; when you choose to follow His call, He will provide the courage you need to persevere in the ministry to which He has called you. In time, when God has used you to save someone's life, you will know that it has been worth the effort.