Mark 16:17 - "And these signs shall follow them that believe;..." 

Because of the tense used with the Greek word for "believe", this verse would be better translated "These signs shall follow them that are constantly believing..."  In other words, these signs don't come automatically just because a person once walked aside and gave his heart to Jesus. These signs follow those who are constantly believing for them to occur. 

Like everything else in the Kingdom of God, signs and wonders are activated by faith. Ask the Holy Spirit to rekindle the flame in your heart to see the supernatural signature of God on your life or your ministry. For the miraculous to occur, He needs you to be constantly releasing your faith -- for it is your faith that activates the supernatural!