# we remain in him and he in us

"we continue to have fellowship with God and he continues to have fellowship with us"

# and he in us

"and he remains in us" 

# By this we know ... us, because he has given

"We know ... us because he gave" or "By this we know ... us: he gave"

# because he has given us some of his Spirit

"because he has put his Holy Spirit in us"