Why do others get lax in their attendance, or drop out like the youth?
Why does Bible study go by the wayside?
Why is prayer so uninspiring, even dull or filled with doubt?
Why do conservative Christian universities grow liberal in time?
We Christians do ourselves no favor if we pretend that the believer's life isn't work. While it is to be lived in the power of the Holy Spirit, we must participate with him. The Bible acknowledges people can grow sluggish:
Let us stop getting tired of doing good, for at the proper time we shall reap if we do not give up. (Gal 6.9 WmsNT)
Heed John Wesley's words from his Journal entry for April 5, 1784:
I was surprised when I came to Chester to find that there also morning preaching was quite left off, for this worthy reason: 'Because the people will not come, or, at least, not in the winter.' If so, the Methodists are a fallen people. Here is proof. They have 'lost their first love,' and they never will or can recover it till they 'do the first works.'
The fire can die if you don't keep it supplied with wood. Then spiritual frost can set in for a long and dark winter.
Notice the warning to the Hebrews:
Let us hold fast the confession of our hope without wavering, for he who promised is faithful. And let us consider how to stir up one another to love and good works, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day drawing near. (Heb 10.23-25 ESV)
Why keep gathering with fellow Christians for worship, instruction and fellowship? Because you need it, and they need you.