"Woe to you, scribes and Pharisees, hypocrites! For you travel across sea and land to make a single proselyte, and when he becomes a proselyte, you make him twice as much a child of hell as yourselves." (Matthew 23:15)
This is not Jesus condemning the making of disciples or speaking the gospel so those whom God has chosen will hear and repent trusting in Christ's work on their behalf. When know this is true because Jesus tells us to go and make disciples of all nations (Matt. 28:19). Rather Jesus is condemning the Pharisees for placing heavy weights around the necks of people by sharing with them with a message of earning salvation by works of the law. What a tragic thing. Jesus says instead of bringing them hope the Pharisees were making converts who were now "twice as much a child of hell" as themselves. No hope is given in the message of earning salvation by works of the law. The law is God's perfect law which all of us have broken therefore we cannot obtain salvation through obedience to the law.
One thing for us as followers of Jesus Christ that we can take away as a positive from the Pharisees: they were zealous to share their message. Yes, they did indeed share a false gospel but we how have the true gospel ought to be even more zealous than the Pharisees to share the true gospel. Our message brings hope to the hopeless. Life to the lifeless. Blind eyes are made to see. The reward is not making people twice the sons of hell but rather sons and daughters of the King of kings and Lord of lords. We bring a message of eternal joy with the Creator of the universe. We ought to proclaim as Paul did, "I am not ashamed of the gospel." Why Paul? "For it is the power of God for salvation to everyone who believes" (Rom. 1:16).
Grace upon grace,