The Holy Spirit, as the third Person in the Trinity is a Person (John 14:26) who is also God (2 Corinthians 13:14), and is Himself the Spirit of Jesus (John 16:7).
The Work of the Holy Spirit in us is firstly, before conversion – when He illuminates the mind of the seeker (1 Corinthians 12:3) and convinces one of one’s sin and need of a Saviour (John 16:8). Secondly, at conversion – when He regenerates (John 3: 5–6) and then indwells the life of the believer (1 Corinthians 3:16), and seals the believer as a purchased possession (Ephesians 1:13). Thirdly, after conversion – when He sanctifies the believer (1 Thessalonians 4:7-8), guides, helps us to pray, strengthens, brings forth His fruit, and equips us for service through His gifts (1 Corinthians 12:4-11).
A truly Spirit-filled person should exhibit love as the primary evidence of the Spirit’s work and fullness. Love expressed through joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control (Galatians 5:22).