The preaching and spreading of the gospel is not an optional work given to us by Christ. What he said was that, go into all the world, and preach the gospel, not if you like you can go into the world and preach the gospel. It is like a commandment, it is what you as a believer have to do. You that are saved, stand up for the salvation of others. Are you ashamed of your faith or you are not up enough to preach the gospel. The bible says: i am not ashamed of the Gospel for it is the power of God unto salvation.
To live is Christ, to die is gain. The bible says that, to live is Christ to dies is gain, being alive for me means a fruitful labor for God. the scripture also says that you should bear fruits, fruits that remain, that lasts, eternal fruit. The only fruit that can last for eternity is the fruit of souls.
Proverbs 11:30- The fruit of the righteous is a tree of life; and he that wins souls is wise.
This is what you have been called to do, even when you are in your working place, whatever you do, winning souls is your priority.
