God has ordered Christians to live an active and fruitful life. Spiritual fruits are the consequences of life with Jesus Christ; they manifest the Lord's nature in the believers.
The most important fruit is love, which principally shows and proves our communion with God. The lack of love makes the ministry gifts and the spiritual gifts worthless.
The other fruits: joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. All of these prove the sincerity of repentance. The total lack of them results in exclusion from the presence and grace of the Lord.
The gifts and the fruits of the Holy Spirit complement and strengthen and authenticate each other.