Charles Spurgeon Commentary Hebrews 3:14

"for we are become partakers of Christ, if we hold fast the beginning of our confidence firm unto the end:" — Hebrews 3:14 (ASV)

For we are made partakers of Christ if we hold the beginning of our confidence steadfast unto the end.

It is not true that one act of faith is all that is required, unless you consider that one act to be continuous throughout life. If a man were a believer once, and if it were possible for him to cease to be so, then, of course, he is ruined. But the doctrine of the final perseverance of the saints does not speak in that way. Instead, it says that he who is a believer will continue to be so—that he who is right with God will abide so even to the end. And unless it is so, we are not partakers of Christ at all. We are made partakers of Christ if we hold the beginning of our confidence steadfast unto the end.

For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end.

You are to hold fast, to hold on, and to hold out to the end; and the grace you need in order to do this is waiting for you if you will only look for it and daily live under the power of it.