The Scriptures clearly show that Christians are expected to grow and mature in the faith, and they should aspire to do so. However, one should not fail to share the simple things of the faith when the opportunity arises out of fear that it isn't 'deep enough' or get so wrap up in deeper things that one fails to share the simple things of the Gospel as seen in 1 Cor 15. Plant or water as you have opportunity. It is God who makes it grow.