I think
Rom12 and the measure of faith pertains to spiritual gifts and maintaining one's place in the Body with sound thinking and without haughtiness as the measure of grace is dealing with in
Eph4. Also see the tie in context re: grace
Rom12:6.
Rom 12:3 For I say, through the grace given to me, to everyone who is among you, not to think
of himself more highly than he ought to think, but to think soberly, as God
has dealt (aorist active indicative: gnomic, apportions) to each one
a measure of faith.
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
Rom 12:6 Having then gifts differing according to the grace that is given to us, whether prophecy, let us prophesy
according to the proportion of faith;
ἔχοντες δὲ χαρίσματα κατὰ τὴν χάριν τὴν δοθεῖσαν ἡμῖν διάφορα εἴτε προφητείαν
κατὰ τὴν ἀναλογίαν τῆς πίστεως
I would suggest that the expression "as God apportions to each one a measure of faith" (ὡς ὁ θεὸς ἐμέρισεν μέτρον πίστεως) is expressed in different words by "according to the proportion of faith" (κατὰ τὴν ἀναλογίαν τῆς πίστεως).
And I would also suggest that Paul intends us to add those to all of the elliptical injunctions that follow, starting with v. 7 εἴτε διακονίαν ἐν τῇ διακονίᾳ εἴτε ὁ διδάσκων ἐν τῇ διδασκαλίᾳ
Rom 12:7 if
having gifts of ministry
differing according to the grace that is given to us, let us minister
according to the proportion of faith; he who teaches
according to the grace that is given to him, in teaching
according to the proportion of faith; etc. etc.
What I see is that we are given a sufficient measure of grace and faith, through Jesus revealing Himself through the word and the Holy Spirit and the church, that we can act upon within ourselves to become children of God and to mature in Christ (Rom. 1-11); and once regenerated, we are given a measure of grace and faith, through the Word and the Church and the empowerment of the Holy Spirit, to administer spiritual gifts that edify others. The ministry gift of faith is exercising a faith that is effective to bring about a miracle for someone else, as opposed to a faith that brings about a miracle for oneself.
What I see is that we gain a measure of faith through what Jesus is saying and doing around us, and that measure of faith differs among believers, depending on how convincing we find the evidence given us by Jesus to inspire that faith. Some believe tentatively, and some believe extremely confidently.
Jesus taught that we wrestle with our degree of unbelief counteracting our degree of faith. So we do have a proportion of trust in Jesus vs. unbelief (trust in other things that conflict with our faith in Jesus).
Mat 14:30 But when he saw that the wind
was boisterous, he was afraid; and beginning to sink he cried out, saying, “Lord, save me!”
Mat 14:31 And immediately Jesus stretched out
His hand and caught him, and said to him, “O you
of little faith, why did you
doubt?”
Peter had faith in Jesus, but his faith in his fisherman's experience of how buoyancy works waxed as His faith in Jesus ability to keep him afloat waned until his belief in hydraulic displacement overwhelmed his faith in Jesus
Mat 21:21 So Jesus answered and said to them, “Assuredly, I say to you, if you
have faith and
do not doubt, you will not only do what was done to the fig tree, but also if you say to this mountain, ‘Be removed and be cast into the sea,’ it will be done.
Faith without doubt can produce miracles.
Luk 17:6 So the Lord said, “If you have faith as a mustard seed, you can say to this mulberry tree, ‘Be pulled up by the roots and be planted in the sea,' and it would obey you.
Even a mustard seed of faith, if it is not counteracted with any doubt, or any faith in some conflicting principle, is sufficient to perform miracles. We don't need more faith, but we need less unbelief: less trust in ideas that conflict with God's truth.
This counteraction of faith in Christ with unbelief is also acknowledged in Mark 23-24
Mar 9:23 Jesus said to him, “If you can believe, all things
are possible to him who believes.”
Mar 9:24 Immediately the father of the child cried out and said with tears, “Lord,
I believe; help
my unbelief!”
In 1 Cor. 10:15 we see that faith can increase, but given that a mustard-seed is sufficient for a miracle, this growth in faith seems more a growth in the proportion of faith vs. doubt, by dievsting ourself of unbiblical beliefs, that an accumulation of some commodity called faith.
2Co 10:15
not boasting of things beyond measure,
that is, in other men’s labors, but having hope,
that as your faith is increased, we shall be greatly enlarged by you in our sphere.
Jas 1:6 But let him ask in faith, with no doubting, for he who doubts is like a wave of the sea driven and tossed by the wind.
Jas 1:7 For let not that man suppose that he will receive anything from the Lord;
Jas 1:8 he is a double-minded man, unstable in all his ways.
Jas 4:8 Draw near to God and He will draw near to you. Cleanse
your hands,
you sinners; and purify
your hearts,
you double-minded.
The disciples has a mistaken idea that faith was some commodity that could be grown, rather than a faculty that could be hobbled by a counterbalancing proportion of doubt. Jesus told a parable correcting this false notion.
Luk 17:5 And the apostles said to the Lord, “Increase our faith.”
Luk 17:6 So the Lord said, “If you have faith as a mustard seed, you can say to this mulberry tree, ‘Be pulled up by the roots and be planted in the sea,’ and it would obey you.
Luk 17:7 “And which of you, having a servant plowing or tending sheep, will say to him when he has come in from the field, ‘Come at once and sit down to eat’?
Luk 17:8 “But will he not rather say to him, ‘Prepare something for my supper, and gird yourself and serve me till I have eaten and drunk, and afterward you will eat and drink’?
Luk 17:9 “Does he thank that servant because he did the things that were commanded him? I think not.[fn]
Luk 17:10 “So likewise you, when you have done all those things which you are commanded, say, ‘We are unprofitable servants. We have done what was our duty to do.’ ”
Jesus seems to me to be teaching here, that God does not increase our faith like a master could increase his servant's power to do his next task by loading him up with more food.
How does a master increase his servants faith/confidence successfully to perform his future tasks. By giving the servant more tasks to perform. God puts faith in His servants by giving them tasks to do and they need to go and do them, trusting in His having put trust in them. So when the Christian asks to have his faith increased, what he is really asking is for God to give him some more tasks to do. And when He successfully does them trusting Jesus to work with him, His confidence in God grows. And even if He stumbles and messes up the task, God's grace and mercy when he is humble and sorry, also encourages greater faith, when God says,
"I'm not throwing you into the rubbish. Let's try something else I have for you to do. Keep trusting Me and trying and you will get better at this. David messed up. Moses messed up. I am the God of infinite chances."