When you are a fan of your favorite football team, say, Barcelona FC and go crazy with its successes and failures, you are, as it were, "dressed in your team", you "put on" so to say your infatuation with the play of your team and even can tatoo on your chest: "I am Barcelona FC".
Same holds here: if you invite the Lord Jesus Christ in your heart and life and He starts working in you, like He worked in Paul, then this working of the Lord in you and your co-working with His working becomes your life, to the effect that just like Paul, you also can be able to say, "not any more I, but Christ lives in me" (Gal 2:20). Moreover, if you will not be able to say this, that is to say, if your Christianity is just a nominal thing and you do not really co-work with Lord's working in you and make the grace of holy Baptism wither in your heart, then such a Christianity will not only not lead to salvation, but will lead to a most despicable damnation, for even in damnation there are gradations - as Dante well intuited in his theological visions in "Divina Commedia" - and pharisees and hypocrites will be "beaten more" than various Hitlers and Al Capones (cf. Luke 12:47), and unlike them their beating will contain also an element of a specific pussillanimous shame.
However, a good Christian, a co-worker of Christ's working in his heart and life can be said to "wear Christ", just like a Barcelona FC aficionado can be said to "wear Barcelona FC", with an important difference that Barcelona FC will eventually betray expectations of all fans, for football is a transient thing, while a wearer of Christ will continue to wear Him and rule together with Him, the Heavenly King, in His Kingdom forever and ever.