Don't hold back.
God's provision is unlimited. How much of our harvest and GDP do we utilize for ourselves? I couldn't say. Without even referring to greed and collusion, the output is so abundant as to be distributed worldwide. We see this in our charities and food banks (local and international). The point is, we have enough to go around. To put food on the table and to feed anyone who asks. The waste is enough to feed the want of some small countries.
Waste not, want not. Spiritually, it's like this: until we are grateful and fully utilize what we do have from God (mind, will, emotions), He can't "open the windows of heaven" (Malachi 3:10) to give us more.
We, as a nation (America), are drowning in products and provisions. But spiritually, we are starving. When Jesus says that "greater works than these shall ye do" (John 14:12), it's assumed that we're already doing the minimum requirements needed to appropriate the blessings of Heaven. "And God requireth that which is past" (Ecclesiastes 3:15). I feel very passionately that God is waiting on us. The ball is in our court and the way to change things begins in our own heart and mind. How much of my day do I bring into the line of God's scrutiny? How much am I even willing to bring into his subjection? The Book of Proverbs says that I should "acknowledge" Him "in all [my] ways" (3:6, more of a command, really). How many ways? All of them. How much of my mental capacity is, as it says in 2 Corinthians 10:5, to be brought into "captivity to the obedience to Christ"? "Every thought". This is stark. Like getting out of the pool after swimming. It might feel cold (it's not), but it's reality. God wouldn't have told us to do this if it weren't possible. In fact, this is what keeps out the riffraff. Without the enablement of the Holy Spirit—which is ours for the asking (all it takes is a simple "please" and "thank-You")—it's not possible. And yet Jesus says "I only do those things that please the Father" (John 8:29). We are called to do the same. I know we're "only human". And Jesus is "all that" plus God, but this doesn't mean we shouldn't be "striving for the mastery" (1 Corinthians 9:25).
God will shore up our perceived inconsistencies if we are making the effort to bring "all things in subjection" (Hebrews 2:8) to Him. It takes effort, sure, but the Holy Spirit has our back. What other endeavor is more important?
"Only one life 'twill soon be past. Only what's done for Christ will last." C. T. Studd