Besides

Leviticus 23:37-38 KJV

These are the feasts of the LORD, which ye shall proclaim to be holy convocations, to offer an offering made by fire unto the LORD, a burnt offering, and a meat offering, a sacrifice, and drink offerings, every thing upon his day:

Beside the sabbaths of the LORD, and beside your gifts, and beside all your vows, and beside all your freewill offerings, which ye give unto the LORD.

This chapter consists of the feasts the Jews were to observe as a part of their worship of the Lord. Every aspect of their worship had significance so every aspect was to be kept. The feasts were more than celebrations, they were lessons played out in life. And they were to be kept, 

• Besides the sabbaths of the LORD, and 
• Besides your gifts, and besides all your vows, and 
• Besides all your freewill offerings, which ye give unto the LORD

In other words, do these and all the rest too. 

I think I have met a lot of Christians who think of their faith as a heap of events piled on them one after the other. They look at living for Christ as a burden. They cannot see the benefit of observing all things whatsoever Jesus commanded. They want to have a little piece of the Christian life but they don't want to add all these other pieces on beside them. 

But Christianity, real Christianity is an all or nothing thing. 

• Ask The apostles who left all to follow the Lord
• Ask the martyrs who lost their lives because they believed
• Ask the Anabaptists who suffered brutality and death rather than surrender their faith

Real Christianity is not this "one or two drops of salvation in a solution of worldliness" blend we see practiced so frequently today. 

May God wake us up to realize that Christianity is more than a few festivals throughout the year. It is a complete change of life in favor of the yoke of Jesus Christ.