Far be it from me to criticize a modern innovation of Holy Mother Church, but I think she made a big mistake going from the one year cycle of readings to the current three year cycle. It's much easier to memorize the letter and spirit of Scripture when we hear the same reading once a year as opposed to once every three years. There's something to be said for quantity being its own quality, but I've got a hunch the average Catholic doesn't know Scripture any better, and probably a good deal less, than his great-grandfather did.
Isaiah tells us of God's promise to destroy death and wipe away every tear. The Lord of Hosts will provide us with the best food and choicest wines on his holy mountain. St. Paul reminds us that in this life we will experience both plenty and want. Whatever our circumstances, our strength is in the Lord in whom we can do all things and God will provide us with what we need through Christ Jesus (what we need won't always be what we want however.) Jesus tells the parable of the wedding feast, where the invited guests spit on the king's hospitality. The king orders his men to invite whomever they meet in the streets. On the night of the wedding, one guest is without a wedding garment and he is cast into the outer darkness where there is wailing and gnashing of teeth.
Isaiah and Paul remind us to be confident in God. Whatever hardships we experience in this life are as nothing compared to what awaits us in the next. Many are called, but few are chosen. God desires that all men be saved, but not all men will be saved because we choose to turn away from God. Jesus came to gather the House of Israel. The Jews were the invited guests in the parable, but many of them turned away from God's invitation to enter the New Covenant. The men whom the king's men recruit from the streets are the gentiles, for as Paul tells us later on, in Christ there is no more Jew or Gentile, slave or free. The wedding garment is righteousness. We cannot enter into the wedding feast if we are not clothed in holiness and virtue. We may honor God with our lips, but if we have not put on the new man and cast off the old, we too will be hurled into the outer darkness.
I'm a weak man, and I can't put on righteousness through my own willpower alone. We need God's grace. We need to be strengthened through regular reception of the sacraments. If we trust not in ourselves but in the grace of God and the love of Christ, then we can do all things through him who strengthens us.