The second gift listed in Romans 12:6,7 is service or ministry. It involves helping the needy (2 Corinthians 9:12,13). It involves service to saints (1 Corinthians 16:15). (In the New Testament “saint” means “Christian.”) And it involves ministry to the lost (2 Corinthians 4:1). As servants we need to not be unnecessary burdens (2 Corinthians 11:8,9). At the same time, we need to be willing to let others serve us when needed. We must not cause offense (2 Corinthians 6:3). We must be steadfast (Colossians 4:17). We must minister with gladness (1 Peter 4:9). We need to understand that serving is not always easy (2 Timothy 4:5). And we must submit to the Lord (1 Timothy 1:12-14).
Jesus teaches his Apostles about service in John 13:3-17.