The most explicitly Trinitarian benediction in the Bible comes in the final verse of 2 Corinthians.
The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all. (2 Corinthians 13:14)
All three Persons are referred to, even if we would tend to want to mention the Father first. Paul attributes something different from each Person, not because any of these gifts can be separated from God’s Triune nature, but most likely because Paul had already attached these particular blessings to a particular Person previously in the letter.
From the Lord, the Son, we receive “grace.” He who is the Master, He who is the Messiah, gives His favor, and the favor is unconditional. In 2 Corinthians 8:9 His grace to us included His becoming poor so that by His poverty we might become rich.
From God, the Father, we receive “love.” His love is more than a disembodied form somewhere up in the sky. The Father abounds in affections for His children and that love came sloshing over the edges of eternity when He the sent His Son and then His Spirit. He loves generously because, as in 2 Corinthians 13:11, He is “the God of love and peace.”
From the Holy Spirit we receive “fellowship.” We are brought into the company of the saints in light. We are made partakers of the divine nature through the Spirit, God’s love is shed abroad in our hearts through the Spirit, and we are united to the body through one Spirit. According to 2 Corinthians 5:5 the Spirit is the guarantee of our eternal life. We will share this fellowship forever.
It’s only by the Son’s grace that we know God’s love, and it is love that defines our fellowship in the Spirit.