I sense a presupposition that using pot is a "worldly" or "fleshly"desire. That using pot is the old, dead thing that passes away and is no longer a part of our new life in Christ.
I think people carry with them a similar presupposition about alcohol use, that using alcohol is the old, dead thing that passes away.
Colossians 2:16-23 lead me to believe that abstinence is the old, dead thing that passes away, and is no longer a part of our new life in Christ.
What I draw from the Word of God, is that the most important thing is that we do not harm our conscience by betraying our convictions. If you feel like it is unpleasing to God for you to use alcohol, pot, or anything, for God's sake don't use it!
As John Chrysostom said :
"Because he eats not of faith. Not because it is unclean, but because it is not of faith. For he did not believe that it is clean, but though unclean he touched it. But by this he shows them also what great harm they do by compelling men, and not persuading them, to touch things which had hitherto appeared unclean to them, that for this at all events they might leave rebuking. For whatsoever is not of faith is sin. For when a person does not feel sure, nor believe that a thing is clean, how can he do else than sin? (Homily 26 on Romans 14)
I wonder how many people use alcohol or pot in a state of mind like this; people who betray their convictions when they use alcohol or pot, or anything for that matter. "A harmed conscience" is the meaning of the word "stumble". We need to be following the Lord from the bottom of our hearts.
To me, that's what is most important, that we stay true to our convictions, that we do not harm our conscience by our acts, that we maintain a clear conscience before God and men.