Since you don't know how the presence of Christ can be in us via the Spirit of God then this shows me along with your strange teaching and legalism that you don't know Jesus and you are not in the faith.
Examine yourselves to see whether you are in the faith; test yourselves. Do you not realize that Christ Jesus is in you--unless, of course, you fail the test?
If you love me, keep my commands. And I will ask the Father, and he will give you another advocate to help you and be with you forever— the Spirit of truth. The world cannot accept him, because it neither sees him nor knows him. But you know him, for he lives with you and will be c in you. I will not leave you as orphans; I will come to you. 19Before long, the world will not see me anymore, but you will see me. Because I live, you also will live. 20On that day you will realize that I am in my Father, and you are in me, and I am in you. 21Whoever has my commands and keeps them is the one who loves me. The one who loves me will be loved by my Father, and I too will love them and show myself to them.”
You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, they do not belong to Christ.
Both Father and Son make their home with the believer via the Spirit the Father sends in Jesus's name. The Fathers promise. The gift of God.