Jamieson, Fausset and Brown on Titus 3:4

4. To show how little reason the Cretan Christians had to be proud of themselves, and despise others not Christians (see on Tit 3:2, 3). It is to the "kindness and love of God," not to their own merits, that they owe salvation.

kindness--Greek, "goodness," "benignity," which manifests His grace.

love ... toward man--teaching us to have such "love (benevolence) toward man" (Greek, "philanthropy"), "showing all meekness unto all men" (Tit 3:2), even as God had "toward man" (Tit 2:11); opposed to the "hateful and hating" characteristics of unrenewed men, whose wretchedness moved God's benevolent kindness.

of God our Saviour--Greek, "of our Saviour God," namely, the Father (Tit 1:3), who "saved us" (Tit 3:5) "through Jesus Christ our Saviour" (Tit 3:6).

appeared--Greek, "was made to appear"; was manifested.