God’s command is— Take now, not presently. It is extraordinary how we debate! We know a thing is right, but we try to find excuses for not doing it at once. To climb to the height God shows can never be done presently, it must be done now. The sacrifice is gone through in will before it is performed actually.

“And Abraham rose up early in the morning,…and went unto the place of which God had told him” (v. 3). The wonderful simplicity of Abraham! When God spoke, he did not confer with flesh and blood. Beware when you want to confer with flesh and blood, i.e., your own sympathies, your own insight, anything that is not based on your personal relationship to God. These are the things that compete with and hinder obedience to God.

Abraham did not choose the sacrifice. Always guard against self-chosen service for God; self-sacrifice may be a disease. If God has made your cup sweet, drink it with grace; if He has made it bitter, drink it in communion with Him. If the providential order of God for you is a hard time of difficulty, go through with it, but never choose the scene of your martyrdom. God chose the crucible for Abraham, and Abraham made no demur; he went steadily through. If you are not living in touch with Him, it is easy to pass a crude verdict on God. You must go through the crucible before you have any right to pronounce a verdict, because in the crucible you learn to know God better. God is working for His highest ends until His purpose and man’s purpose become one.

Wisdom from Oswald

There is no allowance whatever in the New Testament for the man who says he is saved by grace but who does not produce the graceful goods. Jesus Christ by His Redemption can make our actual life in keeping with our religious profession.
Studies in the Sermon on the Mount