Paul encourages Timothy to live in power, love, and discipline and not to be ashamed because of Paul's suffering in prison because of his (Paul's) faith in Christ.
Paul speaks about Timothy's need to start using his gift again as if he were restarting a fire. AT: "to start using again the gift" (See: [[rc://en/ta/man/translate/figs-metaphor]])
"the gift of God that you received when I laid my hands on you." This refers to a ceremony in which Paul placed his hands on Timothy and prayed that God would enable him to do the work he had commanded him to do.
Possible meanings are 1) "spirit" refers to the "Holy Spirit." AT: "God's Holy Spirit does not cause us to be afraid. He causes us to have power and love and discipline" or 2) "spirit" refers to a characteristic. AT: "God does not cause us to be afraid but to have power and love and discipline"