Ῥωμαίους 12·3 Λέγω γὰρ διὰ τῆς χάριτος τῆς δοθείσης μοι παντὶ τῷ ὄντι ἐν ὑμῖν μὴ ὑπερφρονεῖν παρ᾿ ὃ δεῖ φρονεῖν ἀλλὰ φρονεῖν εἰς τὸ σωφρονεῖν, ἑκάστῳ ὡς ὁ θεὸς ἐμέρισεν μέτρον πίστεως.
3 For through the grace that was given to me, I say to each one of you to not think more highly of yourself than you ought to think, but to think with the result that you think reasonably as God has distributed a measure of faith to each one of you.
For through the grace that was given to me, I say to every one who are among you, to not think highly (ὑπερ-φρονεῖν) from what is necessary to think (φρονεῖν), but to think (φρονεῖν) with the result that to think reasonably (σω-φρονεῖν), to each one as God allotted a measure of faith.
The last two “to think” verbs are separated with εἰς τὸ. In Greek, this expression used with an infinitive verb, indicated that Paul is looking for the proper results when one thinks. That nuance has been provided in the above translation. The translation my not be good English, but it tries to get the point across.
As far as the context is concerned, Paul goes on to say that each believer is part of the body of Christ and each one is important to the body and to each other. Everyone has a certain grace-gift that must be exercised. Romans 12:1-8 parallels with 1 Corinthians 12-14. Here, it is a very general form.