Today I saw a picture of a regular ballpoint pen with an opening and closing click at the opposite end to the nib, which moves the ink cartridge. If the ink cartridge is not out the pen cannot be used to write. This is a good reminder that though God equips us to do His work, we are not operative unless we are switched on to willingly serve Him, and to do so whilst trusting Him. There are many verses that tell us this. 1 Corinthians 15:58 says, "Therefore, my dear brothers and sisters, stand firm. Let nothing move you. Always give yourselves fully to the work of the Lord, because you know that your labour in the Lord is not in vain".
