You must be  credible   – Show your Grand babies by example how to be kind, how to be strong, how to be loving, smart Anything just show them and they will imitate.And in fact they most likely will be more loving, smarter, kinder then we could ever imagine for ourselves.

You are not trying to show them perfection, You are showing them how to strive to be a better you every day. They will see you work towards the goal and they will follow your lead

You have to explain why you behave they way you do. What in your life caused you to be who you are. And what in their lives will make them who they will become

You must smile every day. Show your grandchild joy and they will naturally gravitate to joy .

You need to teach your grandchild how important making the right decision is in their lives and in yours. Tell them ways a right decision  and a wrong decision changed your life  

You need to set an example of daily  spiritual/religious practices. Teach them to pray, meditate, yoga, praise . All the ways you express your spirituality