Addressing sin in other people is quite a tricky thing to do without coming off as a complete hypocrite. After all, none of us are completely free from sin. Sometimes, telling people X is sin is quite difficult when we’re conscious that it is a sin we are fairly well acquainted with ourselves. It is difficult to avoid accusations of hypocrisy when we calls X sin, we encourage others not to do it but we know we ourselves have done it ourselves and maybe will. Is there any way to avoid being hypocritically and yet call sin what it is? I think there is.
Framing
Accusations of hypocrisy are absolutely legitimate if we simply frame our comments as ‘X is sin and you need to to stop it’ when we know that we have sinned same way, and maybe will again. But it isn’t hypocritical to frame your concern as something more like, ‘you know that thing you did, I struggle with that too and I’m conscious the bible says we shouldn’t’. There is a difference between accusing someone else of sin that you do yourself and acknowledging something as sin that you also struggle with. One puts yourself above another person; the other on the same side. One is (potentially) hypocritical; the other is not.
Standard
A second point worth bearing in mind is the standard to which we point. It would be hypocritical to use ourselves as the standard. If we aren’t free from sin, how can we call anyone else to put their sin away? But if we are pointing to a different standard – that to which Jesus calls us – it isn’t hypocritical to ask: have I lived up to it? We might ourselves (per the points above and below) have to admit that we, too, have failed. Maybe in the same regard, maybe in different ones, but by that standard failed nonetheless. But it isn’t hypocritical to point to an objective standard and ask: have we lived up to this measure? When we note that it isn’t my standard, and I’m not measuring anybody against me (which is irrelevant), but against Christ, it is legitimate to note where we have and haven’t done that.
Broad vs Narrow
Perhaps you don’t sin in exactly the same way as this person. It is nevertheless true that you do sin in other ways. You might be able to side-step claims of hypocrisy of the ‘but you do exactly the same thing’ variety. Unfortunately, you won’t be able to side-step ‘I might do X, but you do Y’ accusations. If we want to address a particular point of sin, it is likely to be helpful if we acknowledge, though we perhaps aren’t tempted to this particular sin, that we sin in other ways. We aren’t being hypocritical in calling out this sin despite our own sin; we are acknowledging our own sin and putting ourselves on the same side as this person who similarly commits, albeit different, sin.
Same solution
One of the many issues with legalism is that it can only lead to comparison. If we are wedded to justification by law, I may well be a better law-keeper than you. If I want to help you be a better law-keeper, but avoid claims of hypocrisy, I can only really do it by not breaking the specific law you break. Even then, I’m open to the charge if I break any other law. But genuinely trying to help another person be a better law-keeper necessarily invites comparisons and inevitable charges of hypocrisy.
But if we don’t believe justification is by law, but rather by grace, we should avoid both comparisons and claims of hypocrisy. If salvation is not based on my law-keeping, I don’t necessarily need to be a better law-keeper than you in order to note your sin and avoid claims of hypocrisy. I simply need to acknowledge I, too, am a sinner and am seeking help for my sin from the same source at which you can receive help for yours. Namely, justification by grace alone, through faith alone in Christ alone and the indwelling of the Holy Spirit whose help we receive to put away sin. It’s not a question of who keeps the law better or whether I am a sinner or not. It’s more a question of us having the same essential problem with the same fundamental solution.