Martyn Lloyd-Jones commenting on Romans 6:11, So you also must consider yourselves dead to sin and alive to God in Christ Jesus.
We are told to realize, and to hold before ourselves and in our consciousness constantly, something that is already true of our position or status. It is not an exhortation to us to do anything with regard to sin, but to realize what has already been done for us with respect to our relationship to sin. It is an exhortation to us to remember what is already true of us; it urges us to realize what has already happened to us as Christians, those of us who are joined to the Lord Jesus Christ. And what is true of us is that we are already in an entirely new position and standing with respect to sin.
This is something which we have to believe solely because the Word of God teaches it. You do not 'experience' your position, you are told about it and you believe it. That is what justification by faith alone means. We have this Word of God which tells us that this is God's way of salvation; and we have nothing but the Word of God. As we have seen, we have all got to do what Abraham did, as the Apostle has already reminded us in chapter 4. We must just take the bare Word of God, believe it, submit to it, and act upon it. That is what we have to do with this statement.