@Jim B, let me try to reason with you why I see that - a person is told to build up on things spiritually, and you tell me if it is worth while or not worth while.
Have you read these scriptures before by Paul writing to the Galatians?
Galatians 6:7-9
7 Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap.
8 For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting.
9 And let us not be weary in well doing: for in due season we shall reap, if we faint not.
Please take a look here, and tell me if building on spiritual things are not beneficial to a person in their life having chosen to live a life for God and have love for God first, and to love others, with and by walking in faith, by the spirit, in faith of the Gospel of Christ.
Jesus says this to his disciples, do you remember this too?
Matthew 6
Treasures in Heaven
(
Luke 12:32–34)
19Do not store up for yourselves treasures on earth, where moth and rust
c destroy, and where thieves break in and steal.
20But store up for yourselves treasures in heaven, where moth and rust do not destroy, and where thieves do not break in and steal.
21For where your treasure is, there your heart will be also.
So I do believe that a persons spiritual building they build on Christ, will go on with that person in the after life, and God will reward them.
Hebrews 11:6 He that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him"
I believe this all has to do with the spiritual body a person builds up now; strong in faith towards God and confidence in the Gospel of Christ, to live a life for God and to love God and to love others, in Christ - as hard as it is dying to the self as Paul talks about in Romans, and perhaps one other place. It is about dying with Christ, being buried with Christ, and being raised again in Christ.
These of course are my opinions from my understand of scripture and I am capable of being wrong just like any other person but please hear me out on why I see the reason for the life of the believer to be built up on spiritual foundation, in spiritual principles that help them life (through all the body aches, people lost, bad or good experiences - with God in it.