The Lord is well aware that He sends us forth to witness in an unfavorable and even hostile situation, to a "faithless and corrupt age." Nonetheless, He challenges us to boldly proclaim Him and His teaching. If we let ourselves be intimidated by negative circumstances, Jesus will be ashamed of us "when He comes with the holy angels in His Father's glory" (Mk 8:38).
This takes away one of our best excuses for not being Jesus' witnesses. We rationalize not speaking up for Jesus because the people in a particular situation are not open or ready for the Gospel. However, the Gospel itself opens people to the Gospel. People don't need to be ready for it, but we need to be ready for them by obeying Jesus.
Jesus sent His disciples to proclaim the Gospel to all creation (Mk 16:15). They did not "pick their spots." They were not reacting to circumstances, but the circumstances were reacting to them. We don't have to inform the Lord about how hard and resistant are the hearts of those to whom He sends us. He knows the situation.
Our job is to obey Him. His job is to open people's hearts, save them, and lead them into everlasting life. Therefore, in Jesus' name go with the Gospel to all people, even to the "faithless and corrupt."