Note from these verses that the determining factor of whether or not a person possesses eternal life is whether or not they possess Jesus Christ. The Lord Jesus Christ and eternal life are inseparable – a person either has both or neither.
Just as Jesus came to live inside of you at salvation, you went to live in him. Christ is unique in distinction to the Father and the Holy Spirit in that he has a “body” – obviously he had a physical body while here on earth (Hebrews 10:5), but Jesus also has a spiritual body specifically called “the church” in Ephesians 1:22-23 and in Colossians 1:18 & 24. The “church” is not a reference to a denomination or a building somewhere. In Scripture the word “church” is often a reference to all of the people who have ever been saved since the time of Christ. “The church” then, in the generic sense of the word, is the assembly of all believers whether physically dead or alive. At the very moment of salvation you were “added” to this body, “the church;” or in other words, you were “put into” the Lord Jesus Christ.