Salvation is Jesus, believing that He is Lord and thus OBEYING Him. If we believe that Jesus is Lord and the He alone has power to cast in hell or give eternal life, then we OBEY every word that He spoke. All mankind will be judged by the words of Jesus, nothing else.
Being a follower of Jesus means to REPENT, turn away, from sin and serving yourself; and OBEY Jesus. Obedience to Jesus means, obedience to His Spirit that He gives in us, together with our spirit(conscience), guiding us into righteousness, and to His words as written in the gospels. (Matthew, Mark Luke and John)
The great commission, to ALL of those who follow Him is to MAKE DISCIPLES. "Go therefore and MAKE DISCIPLEof all nations, BAPTIZING them in the name of the Father and of the Son and of the Holy Spirit, TEACHING them to OBSERVE all that I have COMMANDED YOU you." Matthew 28:19.
We are all called as witnesses. Refusal to obey the great commission renders us utterly fruitless and ready to be cut off, ready for the fire. If we are ashamed of Jesus, He will also be ashamed of us.
To witness is obedience. It might seem as though it has no effect, you might be rejected by people. OBEY, WITNESS, we are only the sowers, God makes it grow. His words will never return empty, but YOU MUST WITNESS. "you shall be My witnesses" Acts 1:8.
"But his master answered him, ‘You wicked and slothful servant! You knew that I reap where I have not sown and gather where I scattered no seed? Then you ought to have invested my money with the bankers, and at my coming I should have received what was my own with interest. So take the talent from him and give it to him who has the ten talents. For to everyone who has will more be given, and he will have an abundance. But from the one who has not, even what he has will be taken away. And cast the worthless servant into the outer darkness. In that place there will be weeping and gnashing of teeth.’ Matthew 25:26-30.
Our lives must be a testimony for Jesus, we must witness. Our means must be for the building of the kingdom of heaven, caring for our brothers and sisters in need. If we cannot go we must enable those who go and spread the gospel. May we not be found fruitless in the judgment day.