As human beings, we don't like to follow instructions.

. . . We'd rather do it our way. The dreadful swing set construction comes to mind. It's not so different with our lives. Many believe their good works will get them to heaven. God's instructions disagree.

Ephesians 2:8-9 For by grace are ye saved through faith, and that not of yourself; it is the gift of God: Not of works lest any man should boast.

You must be saved to go to heaven. Its by the grace of God (unmerited favor). You can't earn salvation, buy it, or be good enough. 

Isaiah 55:6 Seek ye the Lord while he may be found; call ye upon Him while he is near. 

The invitation is to all sinners. Its to those who have spiritual thirst, hunger, and needs. Is this you? Come to Jesus as you are. Don't clean yourself up first.

The price of salvation is the blood of Jesus Christ shed on Calvary's cross for the sins of all mankind. The same grace that saves you keeps you saved forever, because you're not perfect. The Bible says you are a new creature. Your "want to" changes. 

Only Jesus can satisfy your soul. Ask Him to come into your heart.