It's not a command to win souls. All we can do is give out the Word of God to those who will listen. It's up to the Holy Spirit to awaken them and God to draw them.

(John 6:44 NIV) "No one can come to me unless the Father who sent me draws him, and I will raise him up at the last day.

It's worth reading the parable of the sower:

(Matthew 13:18-23 NIV) "Listen then to what the parable of the sower means: {19} When anyone hears the message about the kingdom and does not understand it, the evil one comes and snatches away what was sown in his heart. This is the seed sown along the path. {20} The one who received the seed that fell on rocky places is the man who hears the word and at once receives it with joy. {21} But since he has no root, he lasts only a short time. When trouble or persecution comes because of the word, he quickly falls away. {22} The one who received the seed that fell among the thorns is the man who hears the word, but the worries of this life and the deceitfulness of wealth choke it, making it unfruitful. {23} But the one who received the seed that fell on good soil is the man who hears the word and understands it. He produces a crop, yielding a hundred, sixty or thirty times what was sown."

I've shared the gospel with people. They rejected it. They know me. They know how I live. They apparently don't want what I have spiritually. But I haven't failed. I shared the gospel with them. I did what I was commanded.