Ques. How can we apply 2 Tim. 2:19-22 to Christians now?
Ans. 2 Timothy applies to individuals who desire to please God. It describes Christendom, and shows what man's failure cannot destroy (see chap. 1:1, 9; 2:19; 3:16, 17; 4:8, 18).
Chapter 2:19, tells us God's firm foundation stands. The Lord knoweth them that are His; and every one that nameth the name of the Lord is to depart from unrighteousness. We are not called upon to say who are the Lord's, but to separate from evil persons; and ways of Christians also, if associated with evil.
Verse 20 describes Christendom under the simile of a great house where confusion is.
Verse 21, calls on the man of God to separate from the mixture, and be thus suited for the Master's use.
Verse 22, tells us to judge our own ways in the words, "Flee also youthful lusts." Then comes what we are to follow,- not men, "but follow righteousness" (that is, practically); "faith" (that is, obedience to the Word of God); "charity" or love (that is, the activity of the divine nature in us); "peace" (that characterizes the man of God). The next words tell us of others with whom we are to associate, "with them that call on the Lord out of a pure heart.”
We do not decide who are the Lord's; He knows them, but we are to associate ourselves with those who manifest themselves in separation from evil; those I am to know, own, and walk with.
The Lord would not give us such instruction if we could not carry it out; only let us faithfully ask Him to guide us to those who keep His Word, and do not deny His Name.