The normal meaning of the word “ideal” is simply a goal, an aim. If you tell someone that it would be “ideal” if he did XYZ, he will realize that you really want him to do these things, but that doing all of them is not absolutely necessary.
Now, the Divine Law is necessary. The negative moral precepts bind always and everywhere, such that to violate a negative moral precept is always a grave evil. Period.
Hence, the Divine Law is not a mere “ideal”. It is not a mere goal, to which it is best that we live up to it, but the adequate doing of which is not absolutely necessary for salvation.
To the contrary: The adequate adherence to the Divine Law in the form of doing what one is commanded positively to do when the circumstances allow and avoiding what one is commanded never to do is necessary for salvation.
Therefore, to present the Law of God as an “ideal” is to confuse this very important teaching, which is the faith of the Church. Why would one want to present the Law as but an “ideal”? Because, perhaps, one does not think that God offers sufficient grace to every free actor? But that thought, too, is contrary to the faith of the Church. And if one despairs of this over oneself, one is doing just that despairing.
But we should not be afraid. Not be fearful. Not read our faith in fear that God is not our Shepherd, does not care for us and supply for us. Not us not understand God’s mercy as his “not judging us because he never supplied for us.” That would be doubly desperate and doubly false. He does supply and he does judge. He judges us according to our works.
Let us listen to words that truly are full of hope, words that don’t cast us down in spirit, words that don’t console us with a false understanding of mercy and judgment but that indicate the truth of God’s mercy: God’s mercy enables true obedience.
Let us listen to John Paul II, Veritatis splendor, art. 103:
“It would be a very serious error to conclude… that the Church’s teaching is essentially only an “ideal” which must then be adapted, proportioned, graduated to the so-called concrete possibilities of man, according to a “balancing of the goods in question”. But what are the “concrete possibilities of man”? And of which man are we speaking? Of man dominated by lust or of man redeemed by Christ? This is what is at stake: thereality of Christ’s redemption. Christ has redeemed us! This means that he has given us the possibility of realizing the entire truth of our being; he has set our freedom free from the domination of concupiscence. And if redeemed man still sins, this is not due to an imperfection of Christ’s redemptive act, but to man’s will not to avail himself of the grace which flows from that act. God’s command is of course proportioned to man’s capabilities; but to the capabilities of the man to whom the Holy Spirit has been given; of the man who, though he has fallen into sin, can always obtain pardon and enjoy the presence of the Holy Spirit”.
These are words that bind us, words that bind Catholics magisterially. These are words consonant with Sacred traditions and with the Holy Scriptures.