When we are baptized, we become saints, that is, we become holy. We receive a new nature (see Gal 6:15) and become sharers in the divine nature (2 Pt 1:4). In Baptism, we begin the process of becoming holy, that is, of being like God (1 Jn 3:2). To grow in holiness, we should renew our Baptisms daily and continue to accept Jesus as our Lord and Savior (see 2 Pt 2:20). Our lives will be a "great period of trial" (Rv 7:14). By turning to the Lord in these trials, we will grow in holiness and in the desire to be holy.
On the path of holiness, we will imitate Jesus more closely. We will be pure as He is pure (1 Jn 3:3). By His grace, we will become holy in every aspect of our conduct "after the likeness of the Holy One Who called" us (1 Pt 1:15). As we grow holier, we will live the Beatitudes and even become worthy of being persecuted for the sake of the gospel (Mt 5:11). Finally, we will either die a holy death and see the holy God immediately and forever, or we will see Him after becoming purified and holier in Purgatory.
The purpose of our lives is to become holy. We are naturally afraid of the adventure of becoming holy. However, the Lord will give us His grace to want to be holy more than we want anything else in life.