{That Christ may dwell} (katoik(8873)ai ton Christon). Another
infinitive (first aorist active) after hina d(9369). Katoike(935c) is
an old verb to make one's home, to be at home. Christ (Christon
accusative of general reference) is asked to make his home in our
hearts. This is the ideal, but a deal of fixing would have to be
done in our hearts for Christ. {Being rooted and grounded in
love} (en agap(8869) erriz(936d)enoi kai tethemeli(936d)enoi). But it is
not certain whether en agap(8869) should go with these participles
or with the preceding infinitive katoik(8873)ai (dwell). Besides,
these two perfect passive participles (from 
izo(935c), old verb, in
N.T. only here and  Col 2:7 , and from 	hemelio(935c), see also  Col
1:23 ) are in the nominative case and are to be taken with hina
exischus(8874)e and are proleptically placed before hina. Verse
 18  should really begin with these participles. Paul piles up
metaphors (dwelling, rooted, grounded).