We find the proof of that both in Scripture, and in the teaching of the Church. The Responsorial Psalm is from Psalm 118. And the Gospel is from Mark, chapter 16, verses 9-15. Then they recognized these men as having been with Jesus. It can help, but it isn't necessary.
Faith demands to be shared, or it dies.
It's not that God will punish him if he doesn't talk about Jesus Christ. It's that he cannot be happy unless he shares Jesus with others. That's the mark of an apostle, and that's what each of us is called to. The Second Vatican Council says the same thing in Ad Gentes, its Decree on the Church's Missionary Activity. Your faith should be cultivated and deepened throughout your lives.