Second Corinthians 13:14 speaks of the grace of the Lord Jesus Christ [the Son], the love of God [the Father], and the fellowship of the Holy Spirit being with us all. The love of God is the source, since God is the origin; the grace of the Lord is the course of the love of God, since the Lord is the expression of God; and the fellowship of the Spirit is the impartation of the grace of the Lord with the love of God, since the Spirit is the transmission of the Lord with God, for our experience and enjoyment of the Triune God—the Father, the Son, and the Spirit.
Jude 20 and 21 may be considered as a "sister portion" to 2 Corinthians 13:14. These verses say that we believers should be those praying in the Holy Spirit, keeping ourselves in the love of God [God the Father], and awaiting the mercy of our Lord Jesus Christ [the Son] unto eternal life [the life of the Triune God]. Praying in the Holy Spirit equals the fellowship of the Spirit in 2 Corinthians 13:14; keeping ourselves in the love of God is parallel with the love of God in that verse; and the mercy of our Lord Jesus Christ goes with the grace of Christ. Mercy and grace go together, but mercy goes farther and deeper to reach what grace cannot reach. God's mercy reaches farther than His grace. Mercy is for persons who are in a miserable and pitiful situation and condition. When the prodigal son came to his father in Luke 15, he was altogether in a miserable and pitiful condition. Whatever the Father did for this pitiful, prodigal son was a mercy to him. Mercy is mentioned instead of grace in Jude 20 and 21 due to the church's degradation and apostasy. In the degraded situation of the churches, God's mercy is needed. When the churches are in degradation, what they need is the Lord's far-reaching mercy.
We are awaiting the mercy of our Lord. The word awaiting implies trusting. While we await and look for the mercy of our Lord, we are also trusting in His mercy. We need to await the mercy of our Lord Jesus Christ unto eternal life. The enjoyment and inheritance of eternal life, the life of God, is the goal of our spiritual seeking. In these verses the Three of the Trinity are involved in the believers' daily Christian life. The entire blessed Trinity is employed and enjoyed by the believers in their praying in the Holy Spirit, keeping themselves in the love of God the Father, and awaiting the mercy of our Lord, the Son, unto eternal life.