Is the majority wrong?

In studying the Bible, it has been commonly pointed out that 1 Corinthians 15:1-6 is Paul's description of the Gospel. Does anyone else find it odd that belief is not mentioned until verse 11 and eternal life is not to be found? Also, why does Paul use the present tense in v. 2 with the condition of IF they hold fast. This seems to imply that IF they do NOT hold fast, they are not presently being saved. While I completely affirm and believe in the preservation of the saints (OSAS-meaning that it is theologically inconsistent for Paul to be saying this), I can not help but to have some questions about these particular things in this text. Any thoughts?