Nobody can be in two places at once

Romans 6:2b (KJV) How shall we, that are dead to sin, live any longer therein?

It is impossible to be dead to sin and at the same time live in it.

Once baptised by the Holy Spirit into the body of Christ...

1 Corinthians 12:13a (KJV) For by one Spirit are we all baptized into one body, 

..the saint is no longer 'in' sin. Instead, they are now 'in' Christ:

Colossians 1:2 (KJV) To the saints and faithful brethren in Christ which are at Colosse: 

Nobody is kept 'in sin' so that God may repeatedly be gracious:

Romans 6:1-2a (KJV) ​ What shall we say then? Shall we continue in sin, that grace may abound? 2 God forbid.

This is a positional change - the person who before their salvation was an enemy of God...

Romans 5:10a (KJV) For if, when we were enemies, we were reconciled to God by the death of his Son,

...is now in Christ and positionally at peace with him:

Romans 5:1 (KJV) Therefore being justified by faith, we have peace with God through our Lord Jesus Christ:

To be in Christ is not exclusive to saints of this dispensation - those saved under the prophecy programme are designated similarly:

Romans 16:7 (KJV) Salute Andronicus and Junia, my kinsmen, and my fellowprisoners, who are of note among the apostles, who also were in Christ before me. 

The distinction for saints today is not the fact that they - exclusively - are in Christ, but how they came to be so i.e. by grace and irrespective of works:

Ephesians 2:8-9 (KJV) For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: 9 Not of works, lest any man should boast.

Scripture calls the positional change from being 'in sin' to being 'in Christ' a translation:

Colossians 1:13 (KJV) Who hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son:

To be in sin is to be darkness, and to be in Christ is to be light:

Ephesians 5:8 (KJV) For ye were sometimes darkness, but now are ye light in the Lord: walk as children of light:

The saint's translation at the moment of salvation moves their spiritual home. Previously it was among the children destined for wrath...

Ephesians 2:3 (KJV) 3 Among whom also we all had our conversation in times past in the lusts of our flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.

...but now it is now in heaven:

Philippians 3:20a (KJV) For our conversation is in heaven;

This should change the saint's perspective on things:

Colossians 3:1-2 (KJV) If ye then be risen with Christ, seek those things which are above, where Christ sitteth on the right hand of God. 2 Set your affection on things above, not on things on the earth.

The work of the ministry is work carried out in Christ...

Romans 16:3 (KJV) Greet Priscilla and Aquila my helpers in Christ Jesus:

...or to put it another way, you must be in Christ to carry out the work of the ministry.