Definition and Context:
Old wineskins refer to the traditional leather containers used in biblical times for storing wine. These wineskins were made from animal hides, typically goats, and were used because of their flexibility and durability. Over time, however, the leather would become brittle and lose its elasticity, making it unsuitable for holding new wine, which ferments and expands.

Biblical References:
The concept of old wineskins is most notably mentioned in the Synoptic Gospels, where Jesus uses it as a metaphor to illustrate the incompatibility of the old Jewish traditions with the new covenant He was establishing. The key passages are found in Matthew 9:17, Mark 2:22, and Luke 5:37-38.

In Matthew 9:17 , Jesus states, "Neither do people pour new wine into old wineskins. If they do, the skins will burst; the wine will spill and the wineskins will be ruined. Instead, they pour new wine into new wineskins, and both are preserved."

Theological Significance:
The metaphor of old wineskins is used by Jesus to emphasize the transformative nature of His ministry and the new covenant. The old wineskins represent the established religious practices and legalistic traditions of Judaism, which were unable to contain the new teachings and the outpouring of the Holy Spirit brought by Christ. The new wine symbolizes the gospel and the dynamic, life-giving power of the Kingdom of God.

This teaching underscores the necessity for spiritual renewal and the openness required to embrace the new work God is doing through Jesus. It challenges believers to be receptive to change and to allow the Holy Spirit to transform their lives, rather than clinging to outdated forms and rituals that cannot accommodate the fullness of the gospel.

Cultural and Historical Background:
In the ancient Near East, wineskins were a common and practical means of storing and transporting wine. The process of making a wineskin involved tanning the hide, sewing it into a bag, and treating it to ensure it was watertight. As the wine fermented, the wineskin would stretch to accommodate the gases produced. Once a wineskin had been used, it would lose its elasticity and could not be reused for new wine without the risk of bursting.

Application for Believers:
The metaphor of old wineskins serves as a powerful reminder for Christians to remain flexible and open to the leading of the Holy Spirit. It encourages believers to evaluate their own spiritual practices and traditions, ensuring they do not become rigid or resistant to the fresh work God desires to do in their lives. This teaching calls for a willingness to embrace change and to prioritize the essence of the gospel over mere formality.

In summary, the imagery of old wineskins in the Bible is a profound illustration of the need for spiritual renewal and adaptability in the face of God's unfolding plan through Jesus Christ.