I did some research on this issue and I accept that this explanation of the withered fig tree is a symbolic or metaphorical way to indicate the decline of the religious system of Judaism and an indication of God's immanent judgement on the façade of religiosity that had permeated it.
However it also represents the immanent end to the OC and the beginning of the NC. God still required His people to obey HIS law but it was now one that was personal in nature and REQUIRED personal obedience. It was no longer the appearance of righteousness, but as Jesus warned in Matthew 23:23, it was a now a matter of fulfilling God's directions.
The following link offers a very good exegesis of this scripture.
Withered Fig Tree
Scripture still shows we are to do ALL we can to advance the cause of Christ. Not works FOR salvation, but works as a RESULT of salvation.
James 1:22-25
22 But be doers of the word and not merely hearers, deceiving yourselves. 23 For if someone is a hearer of the word and not a doer, he is like a person who looks at his natural face in a mirror; 24 then after looking at himself he goes away and immediately forgets what he was like. 25 But the person who looks intently into the perfect law, the law that provides liberty, and continues in it, not having become a forgetful hearer but an active doer—he will be blessed in his doing.