As He who called you is holy, you also be holy in all your conduct, because it is written, “Be holy, for I am holy.” 1 Peter 1:15-16
The desire of God, written through the apostle Peter, instructs you to think clearly and exercise self-control. To do this you cannot allow the cares of the world to muddy up your actions. I very well know that each of us live in this world and it causes great concern from time to time. But we often add to that demise with worldly thinking and concerns of our own.
The command for holiness in your life is not unique to Peter.
God instructed His people toward the same no less than three other times.
You shall therefore be holy, for I am holy. Lev 11:45
You shall be holy, for I the Lord your God am holy. Lev 19:2
And you shall be holy to Me, for I the Lord am holy Lev 20:26
The definition of holy brings you to a place of separating yourself from worldliness (sanctification) and dedicating (consecrating) yourself to God.
It is certainly easy to live secularly. Having been born into this world it becomes natural to you. Sanctification and consecration require thought and a conscientious effort on your part.
To do that takes prayer, Bible reading, and fellowship of others doing the same.